I am among the biggest Metroid Prime -fans you will meet, and as such I am more than happy with just Metroid Prime 3 making the Wii -launch line-up. But that aside, there is still many titles of interest - namely Super Smash Bros. Brawl, Super Monkey Ball, Super Mario Galaxy, LoZ: Twilight Princess, Wario Ware, etc.
All in all, Wii will rule the next generation, easily.