FF13/Versus are not going anywhere.
Future F13 games can be multi if they are on UR3 engine but i doubt it.
If MGS sales enough on PS3 its not going anywhere, MGs on xbox were failures.
Most 3rd party games will be multi, with big franchises on Ps3/360 and spin offs and party/casual stuff on the wii.
Dead rising2 Lost Planet2wil be multui, trusty bell AC6 will go multi.