GTA IV was runner up behind MGS4 so, no it wont win GOTY.
As for GEARS 2 winning, it didnt get a 10 on IGN, and resistance 2 has a higher chance of getting GOTY than gears 2, IGN dubbed it as the better game of the two(both recieved a 9.5).
Either way, im pretty sure GOTY will be MGS4, it also won best graphics =)