EA may not have any plans to release Battlefield on a yearly basis, but that certainly doesn't preclude it from releasing the Medal of Honor series in its stead.
EA has announced that it plans to officially unveil Medal of Honor 2 at the Game Developers Conference 2012 in San Francisco next month. The company sent out invites to members of the press to attend the event, which takes place at The Grand Nightclub at 8PM, on March 6. The pamphlet contains a patch with "MOH" and "1" presumably in reference to Tier 1, the game's protagonists.
Additionally, the Official Playstation 3 Magazine is teasing a "mystery shooter sequel" in next month's issue, with an image of two bullets against a black background.
We can expect to see more information on Medal of Honor 2 once it's officially revealed next month.