We are a 3-5 person editing team, usually working on the same 30-minute project all at the same time. The only way we've found we can do this in Premiere is by breaking the project up into multiple projects that each person can work on separately and then when each project is done, import each of the sub-projects into our master-/final-project.
This of course presents a lot of other issues such as the possibility of two people opening the same project at the same time and ending up with two different versions. And importing projects sometimes makes for a messier master.
I would really like to see the ability to edit the same project simultaneously like you can in Avid MC. I know this won't appeal to any one-person types, but anyone out there in a multi-person environment using Premiere? This one would be HUGE for us--a true lifesaver.
It's probably not appropriate to post a link to a competitor on this site, so I won 't. But the following quote sure sounds appealing:
Experience the most collaborative workflow and get things done on time and on budget. With ______, you and your team can access and play the same files and capture media to the same volume simultaneously, in real time. Since media bins aren’t linked to specific projects or users, you can open bins and access files from other projects—even when in use by others—without having to copy media. And because Unity supports Final Cut systems, you can easily collaborate across mixed editing systems and share media using AMA.
Is this ever even possible with the way the projects are structured in Premiere? It's a different file managment philosophy.
I think Adobe got it right by including the ability to merge video and audio clips into one, a need many professionals have when shooting dual-system sound.
I think the kind of collaboration you're asking for is the next big hurdle standing between Premiere Pro and broad adoption by Hollywood/Broadcast post houses.
I hope it shows up in CS6.