Just FYI for you Diablo 3 players.... yesterday morning I made it well into Act 2... last night joined up with Kludger to test the co-op, he was still in Act 1.... this AM I booted up and it put me back into Act 1 but with all my levels and items, had to rush play for 30 mins to get back to Act 2...

SO... it appears if you join someones game behind you, you will lose that progress... Be Warned.

MAYBE, for co-op play we should have made co-op players.

Just FYI.