I think it will all depend on sales, as someone previously said. If the sales of the PS4/720 are selling much better than the WiiU at the time of launch or better than WiiU's launch, then I can see something somewhat similar to what happened to Nintendo's Wii with 3rd party support.
Even if the sales of Sony's and Microsoft's console sell better, I don't see 3rd parties abandoning the WiiU like they did the Wii however. Reason for that is think the power difference isn't as huge of a gap this time with the WiiU to PS4/720 compared to the Wii to PS3/360. I think Nintendo will be fine as long as it has some solid 1st party games to release on the console to prove everyone wrong, as usual.
Generation 8 Predictions so far.....(as of 9/2013)
Console that will sell most: Nintendo Wii U
Who will sell more consoles between Microsoft/SONY: SONY
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