The Wii U version is lacking some of the big improvements the 360 and PS3 versions will have this year, it may not be a total write-off like FIFA 13 Wii, but it's still something to consider if you're buying a Wii U with FIFA.
The following comments and info come from producer Matt Prior...
"Some of the later improvements on 13 we weren't able to get into the game. So we've got version one. They've got version two [360 & PS3]."
- doesn't include First Touch system, FIFA Street skill system, Player Impact Engine, tactical defending, FIFA Ultimate Team and precision dribbling
- getting the game working on Wii U took up 80 percent of development efforts
- 20 percent of the effort was spent building new features.
The Player Impact Engine and tactical Defending are the biggest losses. In it's favour, the Wii U version has better grass textures, oh and touch controls meant for both casuals, and season players wanting on-the-fly tactics. I think I'll wait till next year.