Zelda is a proven franchise, so its likely to be a AAA ip when it releases this year (which nintendo has promised).
Monster Hunter Tri is a huge game, and even if it may or may not be a huge step up from the PSP version of the sequel of Monster hunter 1, its likely to bring many gamers, and innovate the series with motion controls, and potentially bring the series up to AAA status.
Super mario galaxy 2, Well the first game won game of the year on many sites, so I guess we could say this may be a repeat performence
Metroid is the best FPS ip on the WII, and with other M coming out, I am sure its going to surpass many 3rd person and 1st person action shooters on other consoles.
2010 is showing to be the Wii's biggest year since 2007