What's really sad is that there isn't anything around to fill the void created by the deaths of the Unreal Tournament series and the Quake III Arena games. For some ridiculous reason ID decided not to make a Quake III-2 and Epic Games killed the UT series by consolizing UT3 and then releasing the game as a buggy beta. So, if you're looking for a fast-paced online multiplayer FPS game that will have thousands of people playing it with thousands of custom maps released (like, say, with the original Unreal Touranment) with games like Deathmatch, Capture the Flag, and a vehicle game like Onslaught, along with game types created by users, you're SOL.
I don't know if it's true or not, but I've always wondered whether or not the game companies simply don't want to make a worthwhile FPS like that. The problem is that people could buy that one game and then not feel a need to purchase another game for four or five years. (There are plenty of people today who are still playing the original Unreal Touranment--released in 1999.)