Why? It plays Nintendo games. Do you like Nintendo games and want to play them? If yes, get a Switch. If no, don't. Is money an issue? Wait for a price drop.

Why does the form factor matter in the least? Apart from Nintendo fans making themselves martyrs and Nintendo detractors twisting the knife?

What else does it play? What support will it get? Will 3DS support migrate in a big way? Is it geared for one market, another, or both? It's very important to communicate that in order to start building up hype among gamers, and giving clear targets for devs.

If the only thing it's gonna do is "play Nintendo games", then its fate is much closer to the Wii U than the 3DS. It is not enough for mass market success.

Actually, most AAA games land around the 60 gig mark.  And tens of gigs of that is unoptimized audio that is that size for literally no reason whatsoever other than publisher/develiper laziness.  99% of all AAA games could easily fit on the Switch card if it is 64 gigs in capacity which is entirely feasible.

As for whether it is a handheld or home console, it has features of both but I would say that integrated same-device local multiplayer is a very distinctively home console feature.  And of course to be a true handheld, the device is a bit on the large size.  Also, they ain't marketing this as a handheld any time soon.  Price will be way too high.

I think it's support will be 

1.) Nintendo games (Wii U and 3DS libraries combined, so Splatoon *and* Pokemon on the same system)

2.) 3DS third parties (Monster Hunter V, Yokai Watch, etc.) and probably some Vita devs too. 

3.) A *few* PS4/XB1 downports. Some devs, mostly Japanese ones will be willing to port games largely because of the odds of success for this thing in Japan. So possibly Kingdom Hearts 3, Final Fantasy VII Remake, Soul Calibur VI, Resident Evil 7 ... that kinda thing. But no to a lot of others ... probably no GTA, no Red Dead, no Star Wars Battlefront, no Mass Effect, no Witcher, no Call of Duty. Easier to port games like sport titles (NBA 2K, FIFA) and fighting games (Mortal Kombat) ... maybe from the West and even that I would say is contingent on it doing at least as well as the 3DS did in the West. 

4.) Western indie devs and Western kids IP (basically LEGO and Minecraft). 

5.) Android games, if Nintendo allows it. 

Who said it will compete with PS4/XB1!? But actually can be very interesting secondary console for PS4/XB1 owners. Why would Switch need big HDD when with cartridges they don't need to instal games!? Saying that some of AAA games take whole 128GB means that ond standard XB1/PS4 can be instaled only 4 games, digital or disk (beacues they need to be instaled in order to be played). If developers wants they can easily put 120GB game on 64GB SD card.

Yes, but its not only 3DS successor, its Wii Us also.

And all of that hinges on whether we call it a console or a handheld?

Other way around. The whole debate exists because there is so much uncertainty around which it really is.

You saw the commercial right? It shows what the Switch does. The hook is in the name. Everyone knows what it is. We don't know battery life or library or resolution but we know what the system does. Why would labeling it "console" or "handheld" change anything? If I called Switch a "baked potato" would it suddenly gain or lose third-party support? Would it miraculously grow a second screen?

Problems:

We don't know battery life. (and from rumors, so far, it will be mediocre and below).

We don't know exact specs (got only rumors).

The concept is perfectly clear. Something that is supposed to do both things. The problem lies in communicating everything that is NOT the concept - and I am thinking that this is a part of a bigger problem in functional (read: target market, specifications, support) communication.

Nintendo fans are perfectly excited about it - don't see why they wouldn't be. But all of this, including the iffy statements from western third parties so far is bad for system hype, word of mouth, etc. Nintendo needs to rectify that.

Sony communicated the PS4 at reveal time perfectly. Hype built up, turned to preorders, and look where it is now. This is less "what we call it" and more "clear message". Look at the bigger picture.

I simply disagree. This is most definitely a 3DS successor. If this is a home console, where is the home console portion? There is a glorified video out case, but the honest reality is that this is a hand held that can be hooked to a television. Fuck the fact that it uses moile technology torun the console.

There is nothing wrong with this since I believe Nintendo is really going somewhere with their next home console. When Nintendo released DS, they said they were not killing off Game Boy and that DS was not the Game Boy replacement; rather, it was the third pillar. But, who were they fooling? Only the most dedicate sheep were fooled into believing that lie and now only that same equivalent would be fooled here. The DS line did replace the Game Boy line and I believe this line will replace the DS line.