How can you improve on CounterStrike: Source, considering it's age it's still a very good game. An update would be nice though, graphically. CounterStrike is a pretty simple game, and I think an update would probably ruin that, like making the camera bob up and down when you move etc. But then Valve haven't notably screwed any games up. A game has to be pretty good to make it past a second game, I reckon Battlefield can keep going, Half Life MUST keep going, Call of Duty may have ran out of steam (we'll have to see how Treyarch do with the Call of Duty Vietnam thing). But then a lot of franchises are only on game 2 - Assassins Creed 2, DIRT 2, Bioshock 2...
Well it depends whether they're shelling out for the man himself or whether this soundtrack will be left to Zimmer's "band" of Harry Gregson-Williams's brother, maybe Steve Jablonsky and maybe Klaus Badelt, if the latter two haven't moved on yet. I'll check around for a proper soundtrack release though, having the official soundtrack and not the game would suit me down to the ground as I don't want to rip it.
I never really cared for the COD soundtrack.. Why? Because Mozart and Explosions in the Sky do it for me.
I'm pretty sure they'll stick with the 360/PS3 version, as long as the reqs are high enough to keep it off netbooks and iPhones we should be ok for a while yet