I think it's dangerous to assume that because you can't see a use case for something, that there isn't a use case for something. The Mac Pro fits a specific need, that's for sure, but it's not limited to "Hollywood movie folks."
I'm curious what the intended use case is for this thing? Not being argumentative, just curious.
While the specs would be awesome for playing games, a hardcore gaming PC could be built for much cheaper (and upgrade-able).
I keep thinking the the primary use case is high end video and photo editing, both of which are very resource intensive, and I'm guessing that the best apps for doing this tend to be on the Mac platform.
Or I'm guessing either of the above, and a person really REALLY loves the Mac platform and willing to pay the higher price vs. a PC equivalent, which I find reasonable.
I love the concept of the Mac Pro (both old and new version), but it just seems to have a fairly narrow niche in my view. I could be wrong though.