Alan Wake is a top-tier AAA Survival Horror/Adventure/Shooter. Not an FPS, but has strong TPS elements in it.
Does Resistance 2 even have a 2008 release date? What about Killzone 2? Microsoft still has Huxley coming out, and an untitled Donnybrook MMO project that could be this year, or before both Resistance 2 and Killzone 2 come out.
Then of course, you have the whole GDC 2008 announcements of MS exclusives. MS has hinted that there are a few exclusives that haven't been mentioned yet - there could be some FPSes there.
Back from the dead, I'm afraid.