tuoyo, compared to other consoles, it has been pathetic (there's a discussion about it in other thread right now..) but in terms of sales, Wii third-party games haven't done TOO badly. You're right though, the quantity of quality games is pathetic on Wii.
# of games above 75 on Metacritic (including downloadable):
360: 241 DS: 144
PS3: 152 PSP: 126
Wii: 85