Well, the Wii U wasn't really meant to be unveiled at last E3, it was supposed to be about the 3DS, but then the rumours started and Nintendo was forced to put something together quickly, especially the Zelda Demo, that was made in a very short timespan.
^ This.
Upon watching the entire E3 2011 conference again, It seems like it was sorta rushed. The Wii U announcement was shockingly confusing, even amongst hardcore Nintendo fans, it had demos that seemed to be products that were 50% in production, and the games they showed to the audience that would be coming to the Wii U were incarnations of the 360 and PS3.
They did show off developer testimonies however, but that was probably because they already had dev kits a year prior to the Wii U's E3 announcment.
My guess is if Nintendo wasn't pressured with all the leaks flooding the Internet, then the 'real' revelation of the Wii U would have been this year, 2012.
- Ponkotsu likes this