Seems like Mass Effect 3 save files are going to come in hand sometime in the future as BioWare is suggesting not to delete them after completing the game.
"It wouldn't be a bad idea [to keep your ME3 saves]" said Associate Producer Mike Gamble. "Obviously I can't say anything, but it wouldn't be a bad idea..."
This could mean two things at this point: The saves will be needed for DLC (duh!) or that future Mass Effect games will be based off of your old save files.
Who the hell deletes save files after they beat a game anyway?
that's like the ultimate taboo.