2010 is, based on Brave New Gamer's research, going to be one of the biggest years in gaming. BNG's counted a huge number of games that are either set for release or expected in 2010. This list is, however, incomplete. It including big-name titles that BNG either believes or expects to sell well and/or be well received critically.
Some of these games have been played or tested to some extent, though many are still not expected for release for at least a few months, as of this writing. Should you find a game not on this list, let post in the comments and the list will be updated accordingly.