I like BW_JP's idea of leaving out any below 9 scores for GoW3, because that would totally eliminate bias.
What a joke, welcome back megaman. It's good to have a rampant Sony fan around here since this site is so biased against anything Sony.
Edit: Also, unless GoW3 is significantly different from the first two (which a lot of reviewers have said it's not), an 8/10 sounds pretty fair to me.