Ya I guess I could see that, unified handheld/console

Handheld-960x540

Console-1920×1080

I think they literally could even just take 2-3 of the same system on cores (with the CPU + GPU) and just plop two or three of those into a small microconsole casing -- voila, now you have something with more juice that can run on the TV at 1080p. That would probably also allow Nintendo to get the said System on Chip for even cheaper as it would be in high mass production. 

Are you referring to Wii U's chips?  They'd have to shrink it obviously, but that might work for the HH, not sure how multiple would work on the home con.

Nah not the Wii U's chips. ARM CPU + custom AMD (mobile) GPU that shares a lot of the Wii U's architecture layout, but not literally the same chip. 

Having one SoC that maybe can pump out 250 GFLOPS for the handheld variant, and then just throw 2 or 3 of those into a box for the "console" version. Voila you got a console that can now run the same games for the television at 1080P most likely without much fuss and perhaps more effects here and there for a low cost. 

The iPhone and iPad basically share pretty much the same chipset in a lot of cases. 

Isn't feeding a 720p screen with Wii U quality graphics going to draw quite a bit of power by handheld standards, though, and lead to a lowered battery life?

Though I suppose falling short of HD will cost them the marketing opportunity to name it the "HDS". :P

I don't care what their next handheld is, I will buy it on day one!

Oh no, among these things the devs said, the ones I noted are as common as the ones you noted. If you count it may well be, that wanting the next crazy idea might be the most wished.

While Nintendo does have numerous franchises that are flexible enough to go on either, the individual games are not the same.  The difference is that handheld games have to cater to convenience while home consoles have to cater to long gaming sessions.  In terms of level design, handheld game levels are generally shorter and lighter on the challenge to prevent restarts.  Level design is also more dense to accomondate small screens; levels that would be considered overly claustrophobic are acceptable or even prefered in handheld games because the small screens would make details very dificult to distinguish in overly open levels.  Super Mario 3D Land vs Super Mario 3D World is a good example of this.  Games where levels aren't "completed" but rely on saving will either allow saving at nearly any time (Pokemon, Fire Emblem) or have very frequent save points when compared to console games (Metroid Fusion vs Super Metroid or Metroid Prime to be more contemporary). 

The reason for all this is the convenience factor.  Many people play handhelds in shorter spurts at infrequent times.  A home console will be played for hours on end day after day while a handheld may be played on 15 to 30 minutes every other day (or every day if done on a commute).  As a result, games most accomondate this with the shorter level lengths.  But perhaps more importantly this bleeds over into actual game lengths.  Games like Metroid Fusion, Super Mario 3D Land, and Kirby Tripple deluxe can all be beaten pretty quickly.  In fact, if you sit down and do a long gaming session a la home consoles, you could probably beat them in one sitting.  This isn't a big issue in handheld games though because you play them at your convenience and often for short periods.  In fact, conosle game length levels and game time could be frustrating for handhelds due to comfort reasons and also due to, again, convenience.  If you are playing the game while on the train, it would be bad if the levels take longer than the train ride.  And if you are playing infrequently for short periods, a console length game could take a very long time to beat.

However, tone and pace also play a part.  Handhelds are, generally, more leisurly.  This isn't universal of course, but it is common.  They won't be as serious, lightening things up in presentation or tone (even Fire Emblem keeps things from getting too dark with it's writing).  You also don't want to get too far int sweaty palm gameplay and overly intense moments because, again, the context of where handhelds are intended to go make this inconvenient.  You probably don't want to be in your super serious, game face, potentially cursing mode when on the bus or train.  This isn't to say handheld games present *no* challenge, but rather that it is paced differently than a home console game that can keep the intensity pretty high.

Overall, those are some key differences.  Taken individually, not a huge issue, but taken together it creates a different feel.  Handheld games have to juggle convenience and substance, that's the nature of the demographic and situations that they target.  They have to be engaging enough to warrant full attention, light enough to allow for you to stop at almost any point, challenging enough to be engrossing, easy and/or condensed enough to allow play throughs in relatively short spurts, and structured in a way that allows for play at your convenience. 

And lastly, handheld games lend themselves to more single player focused experiences by default.  Again, it's the convenience factor.  For local, you need everyone to have their system with them and a copy of the game.  That's not easy to be sure of when playing at your convenience on the go.  And online multiplayer takes time to set up and play in many games which, again, is inconvenient if you are on the go and have limited time to actually play. 

I would say Pokemon is an example that takes almost all of these things into consideration in some way.  The game is "open world" but the world design is condensed to make traversing it convenient and easy.  The gameplay is structured so that you can always get somewhere in a short period by catching, grinding (which can net really fast results), battling, etc.  The game is structured in a direct way, but is kept lighter hearted to allow for a relaxing pace should you choose.  You can save at any point obviously.  And while the game is easily accessible, it has enough depth of mechanics and substantial content to warrant lon term play and full attention. 

Compare Pokemon to, say, Skyrim or Xenoblade, two other open world RPGs.  It's not a 1 to 1 match, but the comparison illustrates the point.  You can still save anywhere and there is fast travel *but* both take a long time to finish the core content on home consoles/PCs with long playthrough so it would take far longer on a handheld with short play throughs.  The vast world takes a good bit of time to travel and you have to play for relatively long periods to feel a sense of accomplishment due to the structure.  Challenge in both games can be an issue, but more so in Xenoblade due to certain boss battles and enemy placement.  Xenoblade does keep things fairly light, but Skyrim keeps things pretty serious (though this isn't no Bioshock we're talking about).  And of course, in the case of Xenoblade especially, these games are not as easily accessible.  Skyrim's main challenge is just getting used to the "go anywhere" world design but Xenoblade has pages and pages and pages of tutorials and a myriad of interconnected systems. 

Now let me just say these aren't universal and that you can have some success putting either type of game on either platform.  However, handheld games do have a different philosophy than console games and these are just the immediately obvious examples of differences.  And I think you can see this in a lot of Nintendo's games on handhelds vs games on consoles from the same franchise.  Compare Super Mario 3D Land and 3D World, Metroid Prime and Metroid Fusion, Legend of Zelda: A Link Between Worlds and Wind Waker HD/Twilight Princess/Skyward Sword/etc.  These all have surface differences like graphics, presentation, etc., but they also all have differences in underlying philosophy that reflect these general principles.  Even ports do this when needed, like Majora's Mask 3D, which has made adjustments to account for the need for more convenience when on the go. 

Console games don't have to worry about this and actually often can't follow these patterns.  Console games allow for larger a more open level design, longer chapters, more distance between save points, more intense challenge, sharper learning curves, etc.  Console games even need some of these, especially greater length as many handheld games could be finished in one or two long play sessions (Metroid Fussion, Kirby Tripple Deluxe's main story, Super Mario 3D Land, etc).  And to accomondate this length, these games need more challenge, more depths to dig into. 

And lastly I will say that some of this comes down to demographic expectations.  Even if you could get a home console game to work fairly well on the go, it's not within the expectations of the target demographic, which has come to expect certain types of game design.  But I think a lot of it is an extension of what just makes sense.

Those I think are the most obvious elements.  I will say that this doesn't mean console-like games can't have any success or that games on handhelds always follow all of these, but that they are general principles that govern the relative success of games in the handheld market as well as representing market expectations.  And I will also add that I am not opposed to having the ability to stream a handheld to the TV, but rather having one device trying to be both because, again, the philosophies of the two types of games don't match.  

And such a device (handheld and home console in one) would quite potentially drive the price up too high and keep the specs of the home console version too low for those within just one of the demographics (as sales show, the overlap between handheld and home console isn't very clear).  The library would be "bigger," but still divided into handheld orriented games and console orriented games.  But to accomplish this, the price would be too high and the system to weak for home-console enthusiasts to touch (and the added games that are handheld orriented wouldn't interest a lot of them more than likely because, again, they weren't interested enough in the first place to buy the cheaper handhelds).  On the flip side, the price would also be too high for those who only care about the handheld functionality.  Think about it:  if this device released at $300 (that's awfully low) and was barely more powerful than the Wii U (which will cost peanuts by that time) and weaker than the PS4 (which could be as low as $200), why would home console only people buy it for that price and why would handheld only people buy it when they didn't even go for the $250 3DS? 

Anyway, essay over :P . 

Not really IMO. You have to remember things like the iPad run at a resolution much higher than 1080p (forget about 720p) and run decent looking games at that resolution to boot. 

By late 2016, Nintendo should be able to get a chip better than the Apple A8 that's in modern iPhones/iPads fairly easily. 

Just because the screen is 1280x720, doesn't neccessarily mean every game has to run at that resolution either. Say a port of Zelda U might run at 960x540 on the handheld, whereas something simpler like say a 2D Kirby game (for example) could run at 1280x720. '

It's also why 3D likely will get cut though ... axing 3D means the screen is cheaper, requires much less back light (so better battery life), and less processing power to render images in 3D. Maybe they could release a 3D version later on when costs decrease but I think it's important they get about Wii U level processing power in the first version of their next handheld. 

I also don't think DS/Wii or will be anywhere in the brand/naming next time out. Probably one unified name/brand that they can share between devices. 

So what they want from Nintendo is pretty much a Vita with a unified OS