The Wii has an advantage over the other two systems in that it has a pretty strong userbase in all major regions so a game can break a million units worldwide without selling particularly well in any one region. With that in mind, I expect the following Wii games will break 1 Million this year:
Mario Party 8
Super Paper Mario
Mario Strikers Charged
Metroid Prime 3
Super Smash Bros: Brawl
Super Mario Galaxy
Madden 08
Dragon Quest: Swords
I believe that there is an outside chance that the following games will break a million but they will probably require unexpected strong sales in all regions or in a particular region:
MySims
Boogie
Dance Dance Revolution: Hotest Party
Battalion Wars 2
Fire Emblem
Harvest Moon
Mario & Sonic at the Olympics
Nights: Journey of Dreams
Rayman Raving Rabids 2
Resident Evil: Umbrella Chronicles
Soul Calibur Legends
Metal of Honor Heroes 2
Wii Fit
Wii Music
Edit: On a side note I am quite amazed at some of the games people see as a 'lock' for the PS3 and XBox 360; many of these games would be on my list of 'Games I expected to sell poorly' for both systems ...
