Sony and Microsoft is gonna have to take Nintendo much more seriously this time around.  It seems like with the Wii U they have corrected much of their past mistakes:

1. Going with a HD format capable of 25GB of storage
2. Having a system that has serious leg up on the current systems while not looking kiddish (the Wii U console looks sleek; not toy like at all)
3. Turning the tables around Sony and releasing months/a year ahead of time so that 1st, 2nd, and 3rd party developers gets familiar with the system and have a significant userbase before the competition releases.

Microsoft and Sony will likely keep the same audience they always have. I don't see Wii U massively shifting away the "dudebros" crowd on the 360 for example. Nintendo finally showing up 7 years later with a system that's in the PS3-360 range and finally having some kind of coherent online network isn't going to wow everyone.

The N64 and GameCube errors needed to be understood by Nintendo 16 and 12 years ago, respectively, looking at them in retrospect doesn't mean the Wii U is going to be successful. 

I remember with the GameCube a lot of people said Sony was in trouble because Nintendo finally had an optical disc format (cheap) and was easy to develop for (unlike the N64 and PS2). But it didn't really matter, the GameCube ended up doing even worse than the N64.

I want to see your source. Do we even know who is supporting the other two systems yet? Do we know everybody who is on board with wii u? I know bethesda aren't on board with anything yet.

You seem to think because developers are on board with ps3 and 360 now they have some level of allegiance to them. That they would stand by them no matter what. Well if wii u sells like hot cakes and continues to after the others get here there is no way third parties would make the same move they did with wii. Especially if they see a healthy number of sales the first year.

Third parties are loyal to money. It really depends how the public react. If any of the new systems (and this includes wii u) get off to a slow start we would see the same thing that happened with ps3, 3ds and vita.

my concern isn't that the Wii U can't handle it, more the fact that Wii U dev kits have been n devlopers hands well over a year before any of these games were announced and yet none have been announced for the system. 

Nothings concrete, we are all just speculating here but my thinking is as follows: So many developers have confirmed they're working on Next Gen/Unnannounced systems, go look at any of their job vacancies and its written everywhere. Starwars 1313 is confirmed for an announced platform. Developers like Square are showing of their nex gen engines, showcasing visuals beyond what most people believe the wii U is capable of. When you have developers showcasing non  pc-centric games on very Hi-end PC's it seems pretty evident to me they're indending them for future, more powerfull platforms.

In terms of Wii U support, developers have had the dev kits in their hand for a year and a half, so it does worry me that none of the above have been announced for the system. I agree 3rd parties are loyal to money but that didn't garuntee support for the wii, if the wii U system can't easily support their games, yet they've got 2 combined platforms which will (720/ps4), they may not feel the need to port games down to the wii U. And the perception of the userbase nintendo attracts is also against them as proven by Bethesda. 

To date the Wii U doesn't have a single big (commercially big) 3rd party title announced for it next year. Some may have complete confidence that developers will one by one announcea wii U versions to launch day and date as on the other platforms, but I'm not so sure. The ps3 and 3DS have had strong 3rd party support from the get go,  games began development on the systems long before sales could be judged. I believe the exact same applies to the both 720/PS4 and I believe developers will treat them as a combined market similar to how they have this gen, meaning support is garunteed.

Of course if the Next Gen systems are announced and they're only marginly more powerfull then the Wii U then it'll be a different story.

This is obviously just speculation/opinion, so do yourself doubt that the ps4/720 have a ton load of 3rd games in devlopment right now, games which are being developed with one of the 2 being the lead paltform?

THE FIRST COMMANDMENT OF GAMING -

'THOU SHALT NOT COMMENT ABOUT NINTENDO'

I think in contrast to the wii u, the PS3 and 3DS were garanteed to sell relatively well so developers commited to early big titles.

Even the most ardent Nintendo fan with a degree of intelligence will know that the fate of the wii u is in the lap of the gods.

It could be - as I hope - a resounding success. It can do about OK or it can fail.

I think some developers are playing a waiting game like they did with the x360. Many developers may have early plans drawn up for big titles but before they spend millions they want to see what the market share for the wii u will be like in a few months. Like you I speculate.

I totally agree with the bolded bit.

 That's why if  nintendo released another console that can't even remotely compete with the next PS and Xbox in terms of power or graphics they will be in the exact same situation as the wii regarding third party support.

Nintendo needs third-party support and they know it.

The "only"(ok main reason) reason Nintendo need 3rd party support is to get "the Internet" to shut the hell up

:)

Not saying you are wrong but I would think a far more important reason would be the billions of yen that it will add to their income.

You've brought up good points. I am not sure how much dev costs would go up should they have a massive boost. Some people seem to think more power means higher dev costs but the costs came from building engines for hd game development more then power. I bet developers like epic are already flooding support on those systems so I do agree with the last point.

As for the perception, this stands entirely in the minds of people like Mr. Zelnick. If you actually look at wii you'll see several developers sung praises of sales. Notably capcom. This is how I am seeing things right now. Funnily enough aside from wii no japanese publisher has ever complained at nintendo. I believe this will play out better then wii but there will be problems later. This is what I think will happen.

The problem with wii was partly because of the 'toy' image it gave. It became a haven for shovelware and that didn't help it's image. In this instance touch screen has proven itself with core gamers. It isn't percieved as a 'gimmick' and doesn't 'gimp' the game down. I don't think casuals will bother with wii u. That already gives it an advantage. Shovelware will be migrating to smart phones instead because that is where casuals are.

Japanese support has consistently been good on nintendo. This is why I think nintendo secured monster hunter and dragon quest. They can take japan by storm long before the others get here. That would mean all big publishers there would be drawn there. I think secretly nintendo know they cannot rely on companies like bioware and gearbox to stick around for too long. They will never admit it but they know they can't. One thing they have better control over is taking their good japanese support and raking it in as much as possible. Even the more 'mature' japanese games have enjoyed great success on nintendo. IF others see enough sales to justify staying that would work great but I think there will be a handful that leave later. Not as much as wii though. At worst this would turn into a gamecube situation.