I don't know, Madden and Tony Hawk both sound like they make pretty good use of the Wii, who cares if they aren't exclusive new franchises? I see this as being similar to the N64: it didn't matter if you'd already played Mario or Zelda a million times, the sequels were quite different from anything you'd experienced before. For that matter, Super Monkey Ball is neither new or very exclusive...
Then again, exclusives do perform really well on Nintendo systems. This is interesting, I was actually considering which publishers will cash in on Wii just a few minutes ago, because I'm thinking of buying some stock. Ubisoft is definitely the forerunner, but Red Steel seemed to get iffy impressions from the show. Then again, expectations may have been higher for that game than for Tony Hawk, Madden, or Sonic.
In the end, I have a feeling I may just buy some more Nintendo.

The games that I've heard getting the most praise are mainly Mario and Metroid.