I think the Wii U is an awesome idea in concept, but I won't give any of my faith to it until it's release and I see the software coming out for it. I'm sure I'll still buy on launch because I'm a consumer whore and generally buy new consoles at release. I just like that exciting, new and fresh feel.
I think the only way Wii U has a chance to actually convince people to buy third party games for the system is to get exclusive third party games. I really doubt people with a choice between 360, PS3 or Wii U versions of a multi plat game will pick up the one on Nintendo because of the controller. The controller doesn't seem very ergonomic for playing games like Battlefield 3. If Nintendo wants people interested in third party games, they need third party games you can't get on a Microsoft or Sony platform. Nintendo needs more exclusives than any other console.
Their online structure is also in their infancy. Who in their right mind as an avid Xbox Live or PSN player would jump ship and buy a heavy online game like Battlefield 3 for Wii U when Nintendo has done everything in it's power to make online gaming an inconvenience. Also, 360 and PS3 have achievements and trophies, and people obsess with that. Nintendo has no system like that, and starting one now puts them pretty far behind. It was tough enough for Trophies to try and compete with Achievements in the beginning.
tl;dr: Nintendo needs exclusive third party support, because their new controller isn't enough to convince people to buy multiplats on their console and their online infrastructure has always sucked. I'm sure first party games will still be great though. Where the fuck is Pikmin?