One highlight that comes from this is with copyright protection. I read a story, can't remember when or where, that deals with copyright expirations. The sum of the story said that if software isn't supported anymore then the copyright owner loses the copyright protection.
I don't know the length of time after support stops, or anything else from the article. It makes it interesting though.
Sites could host Slayer's or CASH that contain MS code without retribution. MS has previously stopped support for repairing the original Xbox, so it could be from that date.