At some point, you want something else from your FPSes than the same "watch some in-engine dialogue with your fellow soldiers and then get from point A to point B in a chaotic warzone by killing every bad guy in sight and pulling a few switches once in a while" ultra-linear gameplay over and over again for four titles in a row, only with arabic enemies and modern weaponry in this iteration. Your average FPS offers far more freedom. The concept that made every publication that reviewed PC games herald Call of Duty as the game of the year is extremely tired now, in spite of this game being a really great effort.
Sorry but I'm going to give my gaming time to the other promising FPSes set to be released this year, such as Crysis, Unreal Tournament III and Haze. The first one will offer the greatest real-time gaming graphics ever available to consumers, the second one will refine arcade FPS deathmatch further more and offer a beefier single player mode than the past iterations, and finally I look forward the latter because Free Radical seems set to offer a quality, thought-provoking storyline, and a premise that will be as original as that of Second Sight, something that is very rare in this genre.
As far as prominent FPS games go I think that Blacksite: Area 51 is also going to be released soon, but based on the demo it looked like a very generic sci-fi Rainbow Six clone.