I've had one for about a week now and I'd have to say I'm pleasently surprised but I'm not too sure what to think. I've only been able to spend time with it in spurts because I have not revealed it to the family yet (Son's birthday comes in february).
I wanted to be able to spend some time setting it up and getting all the updates loaded, familar with it. That way he doesn't have to wait when we first plug it in.
A couple quick thoughts.
I'm kinda worried about the thickness of the wire for the Wiimote bar. Looks like something that could easily be sliced. Especially when you have a new puppy in the house.

I think I'd better spray it with some bitter apple.
The controls. I really didn't think much of this till I started playing with it. For the most part the controls are fine. But some combo's are hard on my wrist/hand. Try pressing A AND B while tilting the front of the controller down. I also find it hard to point the Wiimote at the lower half of the screen while I'm sitting on the couch.
The other thing that concerns me is the controls do not lend themselves to more traditional style gaming which may create some problems with third parties. Game designers may try to "force" the new design rather than work out something more natural.
Wii sports was the big surprise. Since I used to play alot of sports as a kid I'm pretty familar with the mechanics of these games. I found it to be fairly natural. I think the biggest problem people have is that you need to pay attention to your onscreen persona and make sure where your hands are matches his movements.
Boxing is probably the biggest example. It's easy to punch and then pull back and your online persona's glove is still making contact. I think people try stuff like uppercuts and roundhouses but I don't think the game is really designed for that. It looks like it is designed for head punches and body blows. There was one time that I accidently did was would be considered an upper cut. But I think what "really" happened was the opponent happened to be leaning forward and a body punch happened to connect with his face.
I think bowling is the only game where I have to be standing up to really do well. The rest I can usually sit up on the edge of the couch. Golf I can literally lay on my side and just "flick" the controller.
Rayman - This one starts a little slow. But the online rail shoots are friggin hilarious. Just like any party games some are fun, others are tedious. I think my son will get a kick out of the outhouse game.

I like the one where you steer the bat and round up pigs.
The other two I have are Zelda and Super monkeyball. Which I've yet to try.
The interface is kinda nice, but nintendo needs to clean it up a little. There are a few oddities like not being able to register from your Wii. When you download a VLC title it does not take you back to where you were. Having to enter your credit card info all the time. I just don't feel comfortable doing that everytime I'm interested in something.
Mii's are pretty cool everytime my likeness turns his head I nearly freak.
Web browser? Well I probably spent more time browsing on the PS3. But I'll have to tinker with it a bit. I was more concerned about trying the other stuff.
Wireless? Fortunately this was easier to set up than I thought it would be. Speed has never been a problem whereas my PS3 had a tendancy to disconnect periodically.
I hate this crap about having to update before going online. PS3 and 360 do this as well. Annoying.
I think my family will most likely spend alot of time with Wii sports. I'll know in about 22 days.
Edited by Shannon, Sun Jan 28, 2007 2:21 AM.