And I'm not discounting it entirely, I just think its stupid to have people looking at some tiny display when they have a huge HD display in front them. It doesn't seem very appealing to me. If you play in low light having the screen come on and off would also be very annoying.
Update: Sources now confirm to IGN the new Nintendo controller allows players to stream entire games to the device from the console, saying it's like a miniature television. The screen size on the controller is also confirmed to be six inches in size.
http://wii.ign.com/articles/116/1162045p1.html
If true, problem solved.