Yesterday I bought my 8th Wii game, Super Mario Galaxy. I have 7 N64 games, so I now have more games for my Wii in its first year than I had games for my N64, ever.
Now, to be fair, two of my Wii games are actually my girlfriend's games, and I probably wouldn't have bought them myself. Also, I have an N64 game for the Virtual Console, and there are at least two more N64 games currently out on the VC that I will buy when I have time to play them. But that being said, there are at least three more already-released Wii games that I will buy when I have time to play them, too.
Regardless of how you want to count, the Wii has been massively more successful in terms of good software.