(the above is an example of what CryEngine 3 can do on PC)
This is a rather interesting rumor being spread around the GAF by a very reliable source close to the industry. The rumor is that Crytek has been working on a Wii U tech demo to be shown behind closed doors to developers at GDC next month.
Link 1 Link 2 Link 3
Seeing how impressive CryEngine 3 has been so far on the 7 year old Xbox 360 with Crysis 2 and a Crysis 1 PC port, it should be pretty amazing what games could look like on the Wii U with it's updated graphics technology and modern GPU. Hopefully after GDC we get some more leaks as to the performance of the Wii U, but I think having Crytek go out of their way to demonstrate their engine on the system might be the most telling aspect.