We've had a Nintendo Wii since Christmas, and it's still a very popular entertainment device in our household. My son is allowed 30 minutes on the Wii a day, but he can bank hours he doesn't use. The 30 minute cap was implemented because the boy is addicted to Lego Star Wars: The Complete Saga.
Personally, I still enjoy Wii Sports. In particular, I like the baseball. I just don't have the patience for Lego Star Wars: The Complete Saga.
This weekend, we had our first issue with the Wii. The sensor bar that we place on top of our television stopped working. It cost me $20 to replace it and I had to buy a wireless model. We're now back in action.
What I would like for the Wii is a quality hockey game, ideally something from EA. Now that would be cool.
30 minute per day with banking capabilities is a great idea! It limits playing, but also makes it so that kids don't have to play every day (if it were a daily limit with no banking), because the banking can be accumulated :)