Badassbab on 07 February 2009
I highly doubt Mass Effect trilogy will come to the PS3.
http://www.gamedaily.com/articles/features/bioware-and-pandemic-on-the-ea-deal/71035/?biz=1
I know it's an old interview but Bioware did state they want it to be a 360 trilogy exclusive. The last thing a developer wants to do with a big budget triple AAA game is spend time and resources on optimisation for a pain in the ass platform 
I'm sure it will be timed exclusive as it's likely the PC will get it 6 months down the line after release.
