I own and to a degree enjoy my Wii U. Here's a mini-review for anyone considering one. My opinions.
The gamepad: It feels great, it works very well, it's fun with Zombi U, I'm just not sure when else I'll use it except for the game or two a year that really develops for it. I knew from the beginning it was going to be a haven for tack-on controls or use just like the Wii-Mote was. If there's no proven return on an investment, third-parties for the most part are not going to develop much for it.
The games: Everyone's taste is different, but Nintendo will over the course of this system's lifespan put out some good first-party games. We'll see Samus, Link, Donkey Kong, 3D Mario and others in HD. I'm already excited for Lego City, Rayman Legends, Monster Hunter, Wonderful 101 (is this out yet?). Zombi U is a LOT of fun. I love it. I also own NSBMU, which is good, Darksiders 2, which makes decent use of the gamepad, and Nintendo Land, which I haven't opened.
The system's extras: TVii is pretty worthless and slow, imo. That's a let down. MiiVerse is cool and integrates very well. If you have kids that use the TV a lot, having the option to play on the gamepad alone is fantastic.
I will say I would not have bought the system if I didn't have over $1,000 in Gamestop credit. I would not have shelled out cash on it with NextBox right around the corner. But as it stands, I like playing Nintendo's games, and this is the current system on which to do it.
P.S. - Remember long ago when there were no achievements or trophies and people played games because they were fun to play? Oh yeah, every other generation except the current one.