User blog comment:Kaloneous/Mass Effect 3 Ending DLC Denied and PAX/@comment-4692902-20120406084952/@comment-1388547-20120406160634

It's not a matter of the capability of the system running it, it's a matter of all the hours the writers, voice actors, and animators would have to put into making all the content. It would just be too much work for them to flesh out all the possible ways the story could continue after ME3.