For me personally im going to say Ninja Gaiden 2 will be my GOTY by a million miles.
Games with a good shot at GOTY awards
Brawl
MGS4
GeoW2
Fable 2 (really depends how well the co-op goes I think)
Spore
Starcraft 2
GTA4
NG2
I would say Gta4, MGS4, spore and starcraft are the main contenders though. I get this feeling game sites are going to moan that GeoW2 hasn't changed enough (yet funnily it will probably change more than starcraft to starcraft 2 and MGS3 to 4). Maybe if gears has all the stuff in the tech demo, destructible environments, hundreds of enemies possible then it could be up there though. Would definetly put a dent in MGS4 chances if it's being compared to GeoW2 and gears has incredibly interactive environments.
Brawl I can see getting nominations as I suspect a lot of editors will likely still be playing it whenever friends come over. Spore because it's innovative. SC2 because it's SC2, will definetly win every single award in Korea.