Just the fact that a friend can play with you at the same time is insane. I mean someone could buy Call of Duty Ghosts and one of their friends could play the game with them at the same time. That in itself would literally almost cut all game sales to half. Add on top that 9 other people could play the game anytime someone else is not playing could potentially cut sales by several times more since people could just form a group, buy one game and alternate when they play that game.
I just don't see how this could ever be possible without some form of major caveat. I can't even imagine how 3rd parties are so against Sony's traditional way of letting people play physical copies of used games and they could possibly allow this, which would cut game sales MAJORLY. If I read the print in the Xbox Wire details, it said that game sharing could be turned on or off by publishers. So at best I could only see this as a feature used by 1st party games. 3rd parties probably won't want to have anything to do with this.
