As a recruiter who has worked in the ECM/EDMS space for more than a decade, I'm beginning to hear talk that I've never heard before from my Documentum managers: "Do you know of anyone who's done SharePoint?"
You're doing stuff (that's my technical term) with Microsoft? I ask. These are people I've grown up with in the EDMS space and back when they were developers Microsoft was a bad word.
Was that courtesy of Documentum's Desktop client, lack of MS being OpenSource, or developer rebellion? Who knows? But now those very same people are saying that SharePoint and MOSS are better solutions for smaller projects...
So being the researcher that I am, I google and AlltheWeb the web and find that there are now Microsoft Vs. primarily Documentum and OpenText fed solutions for FDA submissions. I talk to the Infrastructure owners at my Investment Banking clients and they're still talking Documentum (and many on an Enterprise level) but the development efforts seem to be SharePoint and MOSS oriented. What does this mean? Maybe nothing. I certainly haven't taken a scientific statistical sample or anything, but...
No need to panic if your career is based on Documentum of Liquent-based excellence; I don't think we're moving to an either/or. It might be all about integration and collaboration, or not.
I'll be researching this further and asking people to weigh in. If you want to, please do. If your post needs editing, I'll oblige.