Game Informer and EGM are both currently playing through the review code of Mass Effect. EGM's review is supposed to come out on the 30th of this month, and GI's review is rumored to already have been leaked. Both the primary score and the second opinion came in at 9.75 according to the source, Sillelak.
Quotes:
"One of the greatest science fiction stories ever told, and a new benchmark for video game storytelling."
"Bioware's epic also has the richly detailed environment of Gears of War, the deep exploration of Oblivion, and a fictional universe almost as compelling as Star Wars."
No one has produced a scan of this review, though, so take that for what you will. If it is true, then great. I'm more excited for this game than any coming out in the next year, so I'll be thrilled if it turns out as good as they're saying.