The Wii has a lot of potential. I think that the control scheme is second-to-none, and that after Mario Galaxy (which showed just how effective it was) we ought to have seen a proliferation of good third-party add-ons. As it is, Nintendo is carrying the console itself, but it's proven itself fallible. It's still the single best game developer in the world, and its design team is head-and-shoulders above the competition. But the rest of the company isn't quite as top-notch, and it shows, and it unfortunately means Nintendo's ridiculous advantage over Sony and Microsoft is being entirely wasted.
Their online gameplay was half-baked from the start. The day I got my Wii (2 days after it launched) I also bought Madden, only to end up pissed when I realized there was no online connectivity. It took forever for that stuff to actually work, though I will say that now that it's there, and unlike Xbox it's free, it's pretty nice.
I'm not a fan of the new experience either in one respect: if you're going to force me to choose an avatar (which is annoying) at least make a creator as good as Nintendo's. I find myself unable to make reasonable approximations of anyone I actually know. Also I don't care for where it starts you out now, on that little shopping area. Other than that I find it generally a more efficient navigation system.
Also, Worms on XBL Arcade cost $5 and is my favorite game ever.