I doubt that KH3 will go to PS3 exclusively. Sony isn't in a financial position to pay for an exclusive deal, and SE no longer has the relationship it once did, so they won't be so generous as to throw Sony a bone.
I'd expect to either see a XB360/PS3 version, or a Wii version. Its hard to tell. KH markets itself to a younger crowd with the Disney references, so it might allure a lot of those new Wii owners. KH3 with motion plus could prove interesting.







