Halo 4 to be Multiplatform?

[ZaP~]

isn't Halo already multiplatform with PC? [But as Timed exclusive] Well, Halo 3 not yet, but the others have been.
But the PS3 owners won't like it
X360 owners won't either
Wii owners don't have hopes that Halo 4 could play on Wii
They could do a DS spinoff, it could help with the "casual gamer" and get more hype (even if it seems almost impossible to get more hype than the got by Halo 3)