Someone on Reddit has posted a story that says EA's surprisingly weak support for the Wii U a year after appearing onstage with Nintendo at E3 is the result of a disagreement over the Nintendo Network.
This is a very insubstantial rumor, posted by a reddit newbie (quoting "trusted friends who work at EA") who appears to have posted nothing else on the site, and I only report it here because EA's turnaround was so striking and I haven't seen any good explanations for it.
The story is that Nintendo asked EA to help them build their core online system, but that when Nintendo showed them the finished product, EA tried to sell them on making Nintendo Network part of EA's Origin content distribution system. When Nintendo said no, EA lost interest in the Wii U and pared back their offerings to a bare minimum, deciding to wait to see how the console did before they committed to more games.
Yeah, it's a really thin story; a couple of commenters on reddit referred to it as "fanfiction," and a comment at the beginning about putting out the information to "get the pure truth from EA" sounds a little troll-like, but until someone comes up with another explanation for why EA is offering such lackluster support for the Wii U (2 sports games and a port), I can't reject the possibility outright that there's some grain of truth in here.