Don't forget that Nintendo has hired on atleast 1 ex-Crytek person which would be a good way to get inroads to the Crytek expertise when it comes to pushing hardware and making graphically impressive engines/games for HD machines.
If Nintendo can get Crytek to make their Gears of War/Halo/Uncharted and show that using CryEngine 3.4 (or 4 or whatever) can produce games that graphically surpass PS360 without a doubt and even scale comfortable with ease towards the next MS/Sony system, CryE could easily become the UE3 of next gen as 3rd parties will want to use the engine that allows them to make 1 game and port it to all systems.
Assuming what Epic said was true "They are not building UE4 for Wii U and an interested 3rd party can do it themselves" which I don't fully believe because I've seen something that suggest there are, at the very least, dev tools for UE4 on Wii U even if a fully optimized engine is not in place. I also highly doubt that if the Wii U is capable of running UE4, even if it isn't with all the bells and whistles activated, they won't just sit by and let Crytek take the crown without a fight (assuming CryE becomes the Wii U graphical showcase engine) by not releasing an officially supported version of UE4 (lite, mobile, etc etc).