I think it would be great to have some sort of collaboration capability built in. A few examples in the following list.
1.) Skype-like video ability to communicate with others at a remote location. not completely necessary, as you could just use a secondary system for this part.
2.) The ability to view and control the reason software remotely for editing, recording, or whatever. You could assist a vocalist at a remote location if you are a producer and can't be in the same location.
3.) The ability to play from your own timeline in full quality so a remote location can hear what you hear. Using Skype now just plays through my speakers and then into my mic, then smashed up real good in Skype and sent to the other computer. So if you're laying down tracks with someone else, you can share stuff in full quality in near real time.
4.) Could be interesting to have a sort of project collaboration system where other users could offer up ideas (lay tracks and make alternate edits) on your project and YOU being the producer can decide what you would like to use or not. Kind of like a social networking music project system.
Anyway, maybe someone has already thought of it, or there is a good reason nobody has. Either way, just another one of my random thoughts. Don't flame me too bad :-)