In spite of Mass Effect shortcomings it was the best gaming experience I had last year. That's not to say it was worthy of GOTY. Plus I didnt play any PS3 titles since I dont own one.
As for ME2 I can totally see it as GOTY. If Bioware has fixed the kinks as the early reviews indicate it is a game that stands alone. Nothing else can compare to ME's blend of storytelling, atmosphere, action and in game exploration.
To the people saying it doesnt have much of a chance because it is an early 2010 release and will be overshadowed by later titles, dont forget Bioware plans to release a whole lot of DLC. Unlike with ME1 this game was specifically designed to make DLC add ons easy and functional. If the DLC is up to Bioware's standards and is released in a timely manner and frequently the game will remain in the spotlight throughout the year.