EA are just cutting off their noses to spite their face...but I'd say it's a pretty safe bet that they'll invest in Wii U ports after the PS4 and 720 are released, I can see the Wii U having an installed userbase between 10 and 15m before the end of the year and development costs will probably rise so they'll want to spread that cost across as many platforms as possible.
A price cut in November combined with the releases of 3D Mario and Mario Kart should see consoles flying off shelves.
The one platform I'm concerned about regarding third party support isn't the Wii U but the PS4. Squeezing in 8GB of GDDR5 is a huge mistake, and their GPU isn't going to be cheap either. There's no way that Sony are in the position to make a huge loss on each unit sold, it's going to be over 400 dollars/pounds imo. The price combined with the CPU and GPU being on what's likely to be a 32nm or 28nm process means there's going to be a lot of wasted silicon so production is going to be slow. The PS4 is a disaster waiting to happen imo.