I looked around because I love the music in the game, and I noticed, there's the OST's floating around the internet with all 42 tracks, and the itunes release with only 15.

While the itunes release has proper artist tags, the 27 extra tracks on the OST version have no artist tags.

Can anyone tell me which of the composers does each piece?

I believe Hans Zimmer is the primary composer. Here's more information on Amazon: Cysis 2 Original Game Soundtrack.

hanz zimmer only did a few tracks

Yes, that's why I'm asking about the 27 others, and which of the other 3 composers did those.

Should I just wait for the itunes/amazon release of the 2-disc version to find out? Could anyone tell me which composer does which track? I can only find that info for the first 15 tracks.

Mr. Zimmer is the sound track for Kung-Fu Panda.

Now that might sound really lame if you've never seen the movie, but the music and Foli (spelling?...soundFX) are simply amazing.

... and no, I'm saying that Zimmer did the sfx.. I was just lumping them together.