"all because of Lazy Game Developers"
""Seven Seraphs," "Osiris," "New Monarchy," and "Dead Orbit." These are copyrights for game titles that Bungie has recently placed. It will be multiplatform including PC. Bungie has signed a 10 year contract with activision.
And they are not lazy! Bungie wants to do multiplatform work, thats why they left Microsoft. The reason Reach and Halo 3 are only on the 360 is because it sells 360s, for some people, the only reason they don't get a PS3 is because of Halo, once they have a 360, they then buy into other MS content, so Halo sells 360s, its self, and eventually other games because the person has a 360.
Bungie is working on a new game / engine that should be on PC and the other consoles.