Locking games to accounts
I can see XBoxers attempting to continue game trading by having a throwaway user account for each game and trading those.
Nickname/gamertag/whatever: Halo 9
123 Fake Street
Beverly Hills 90210.
Then MS will crack down on accounts that only have one game registered to them, the internet mobs will go off their tits and someone will start a class-action lawsuit against MS for all this.