User blog comment:The Milkman/No More Mass Effect/@comment-30303790-20120609084347

I can think of some work arounds for the fates of a few key races. Races that are lesser known could be introduced with "We found lost colonies and refugees" and since many of the fates of races where mini-quests of fetch quests in ME3 it's easy to write around that. The Krogan and Rachni, assuming either survived your play through, could be set to minor roles with them being mentioned very briefly as species in a probation like state where they must survive on their respective planets with limited contact with the rest of the universe. Explained away as "teaching" population control. If a game were set far enough in the future other races (much like known characters) whose lives were left in Shep's hands could be killed off by wars, time, and other major events. Cheap, but effective.

Personally though I would like to see the Mass Effect Universe stop now while I still have fond memories of the series as a whole, and I worry that adding new games would be like the ME3 ending stretching through hours of game play.