Nintendo is obviously going for a different business model than Sony or Microsoft, and only time will tell if they're successful. On that note the Wii seemed gimmicky to me until I really sat down and picked up some triple A games (Lego, Zelda, Mario Kart), and then I grew to accept it, even if I didn't love it.
To answer the OP's question, it is not time to buy a Wii U. That time will be in a year / year and a half when it has gained momentum. Developers always have trouble developing for a new Nintendo console, because they are generally different that Sony, Microsoft, and especially PC. However there are a lot of developers who rock touch screens (Android / iPhone) so if the big studios hook up with those guys they can put the Wii U through its paces.