Bungie says, No to other platforms.

[solidarii]

Bungie is not a great developer anyway, I will never understand why so many people like Halo. Halo completely sucks compared to the other shooters. Bioshock, CoD4, Crysis, and Gears all blow Halo away. When Bungie makes something good that is not Halo it might matter, but until then, who gives a damn...