I can't wait for Epic Mickey. It's my own personal most anticipated game of this year.
Mario Galaxy 2 and Metroid are going to be outstanding as a given, and there is a slew of other great titles, but Epic Mickey is just a wild card with the potential to be a true surprise.
There was a flurry of excitement about it for a couple of weeks in 2009 while Specter was regularly releasing tidbits and interviews, but it's mostly died down now. But I look forward to the excitement slowly mounting up again later this year.
(Of course if Zelda Wii came out this year...)