I checked out his IMDb page, and there's no credit for Mass Effect 2. I found an interview with him from Sept where he "hopes" that he'll be in it...I'm definitely overreacting, but seriously that man could read the phone book and make it compelling. Does anyone know if he's confirmed?
There was an interview awhile back where he said that he had not been called to return yet. That was at least three or four months ago, though. Considering the ending of the first Mass Effect, I highly doubt he wouldn't return. There is always a possibillity, of course.
IMDB isn't exactly gospel, there's just as much bullshit on there as there is legitimate information, so using it as your basis of fact is pretty fucking thin Riggs.