There's one thing you need to understand about the PS3-

The registration code included with the PS3 version needs to be registered to your original PC account in order to play the same account on both platforms. In other words, odds are you'd need 2 copies of the PS3 version in order to play 2 different accounts on both platforms. They do this to insure you actually own a copy of the software for the platform you're playing on to combat piracy (which in this case, it sort of works because its account based not disc or software based)

They haven't mentioned anything since they were first talking about the ps3 version, so it may be that this is changing (though i doubt it) but this is how it was originally planned. This is something a rep should probably clear the air on.