That ultimately depends on how much of a market PS4 and 720 manage to carve.  I honestly don't see PS4 making much of an impact; Sony has lost a lot of its luster over the years, and its third party support is dwindling, especially in Japan.  I have a feeling they won't be a threat to Nintendo this time.

Now for 720, that may be more of a reason for concern, but mainly for Western third parties.  That's the only area where Nintendo still may continue to have trouble.

But Japanese third parties should support WiiU just fine.

Being blindsided by a PS4/Xbox Next which becomes extremely popular like what they did with the Wii to the PS3/Xbox 360. Their competition isn't going to underestimate them this time and there is a question of how much of the Wii's success can be repeated and how much was simply a fad/novelty effect. It really depends whether a killer app can be found for high performance or some new peripheral introduced which really takes off.

The biggest obstacle Nintendo has to face is the same obstacle Sony and Microsoft has to face next gen. Games and 3rd party support. The Wii U is competing more with the PS4 and 720 than it with the PS360. So the fact that it's not getting all 3rd party support is not doom. The question is what next gen console will get it, and yes the Wii U is next gen. The fact is no one really knows. Unless anyone has a crystal ball. There are so many possible out comes that any predition is just speculation. We could see the same wii to PS360 situation. Or the Wii U could be the lead console because of too high development cost if the PS4 and 720 are as powerful as some are predicting. Only time will tell.

People really need to stop worrying about developers having problems when the PS4 and 720 have been released. It's going to be easier for them to port between the Wii U, PS4 and 720 than it currently is to port between the Wii U, PS3 and 360 due to the consoles having a similar architecture. You might even see the Wii U being the lead platform due to it having the largest marketshare and being the least powerful machine. It happened in the 6th generation with the PS2.

The biggest obstacle for Nintendo next generation is not knowing what the others are going to do. They had to take a 'leap of faith' with the WiiU and hope that whatever Microsoft and Sony put out will prove to be less popular. The challenge for them is to anticipate what will happen and succesfully overcome it.

Third party is not a real obstacle, maybe only if they aim to 'dominate' (but even then). They've proven three generations in a row now that they are able to at least keep themselves afloat and profitable.

Because that was a huge obstacle for the 2600, NES, PS1, PS2 and Wii right? Can throw all handheld winners in there too if you like.

I am not sure about this whole no third party support thing, this is just plain false. there are already plenty of third party games so far, and it is just one month in. Already in the launch window many franchises have launched which have not been on Nintendo consoles before such as Assassin's Creed and the new Ninja Gaiden series. There is already going to be greater third party support than what was had on Wii, and significantly greater support than what was on GameCube and N64. Ubisoft, this generation, looks to be shifting over to Wii U as their main console, the only ones who probably won't are EA/Activision/THQ - but they're still showing greater support than they ever have on an Nintendo console.

Anyway, what I think their biggest obstacle will be is marketing the Gamepad the same way as they marketed Wii Remotes. It's much easier to hand out a bunch of Wii Remotes and give everyone a try. Not so with the Gamepad. It will be much more difficult.

anyone who has played a handheld device and watched TV at the same time will realise why the wiiu is a bad idea. it causes strain to constantly refocus.