I'm not claiming to be an expert or have any inside info, but my guess would be that Nintendo has severly isolated themselves from cross console titles.
First off, from PC-Wii U? Not very likely unless the publisher is particularly adamant about it. The NextBox and PS4 are VERY likely to see tons of cross platform titles with PC simply because they have adopted a x86 architecture, essentially birdging the rest of the already small gap between game consoles and home pc's. It's very fair to call the ps4 a pc. Granted it's a specialized pc, but there's little that places it firmly in the realm of the "game console" as we have understood that term in the past. Nintendo, on the other hand, very much still is.
And the other issue I'd bring up is the potential that I somewhat expect to see far less cross platform title PERIOD. Until more is known about the next xbox for sure, we can only make these arguments based on rumors. However, this gen is shaping up to be very strange. It looks like we're going to have three consoles with actually very different hardware specs. We have an industry that is already very unwilling to take risks with their games simply because the price of game design has become exorbitant. Look at the problems facing cross console titles from xbox360 and ps3. Most of them were native xbox games that were then ported (poorly) to the ps3. THis is because ps3 architecture was so different, and the cost of making very specific changes so detracting,t hat publishers were unwilling to do it. Nintendo has positioned itself this way, this gen. Sony and Microsoft have consoles coming that are pc's, Wii U is still very much it's own proprietary device and software.
I'm not saying you'll see none, but, if I had to wager a guess, I would say this gen is going to be all about first party games and third party exclusives. And frankly, I'd bet dimes to dollars Nintendo will be the console of choice this gen for that reason. It will be out of left field if either SOny or Microsoft suddenly have super high quality first party franchises break out the way Nintendo already does.
Of course,we'll have to wait and see.