> This means that I can coop with my friends (almost) anywhere in the world even if they havent bought the game! I think this will be a huge feature.

Everything else you've said is correct, but this is not true. Unfortunate, but understandable.

"The only limitation, it seems, is that only one person can be playing the shared copy of a single game at any given time."[1]

[1] http://arstechnica.com/gaming/2013/06/microsoft-defends-the-...