Got my Wii U today, hooked it up, updated it, played it for a few hours. It's pretty great. Great games, great controller, loving the ability to change my TV channels and watch TV while playing the games right on the controller itself. Miiverse is fantastic. It's a social network built right into the system where you can add friends/discuss games. Every game has its own "forum" where anyone who owns a Wii U can post and discuss that game, asking for help or just chatting about it in general, it's all done via the touch screen on the controller, you type/discuss/search the Miiverse like you would search an internet forum with an iPad, and you can access this in-game. You can also access your TV, your browser, and everything else in-game as well.
The Walking Dead is out but I didn't download it yet, going to play and beat it tomorrow.