>for movie studios
You have to wonder how many you could reasonably expect to sell that way, though. Everyone in this thread is talking about some upper-elite of pro computer users (above your ordinary multi-six-figure developer salary on HN), but at only $6k per, that's not any way to make money. If that's really the target market, I would worry about making my design money back, let alone making a profit.
So I have to assume that that's not quite true: it's a computer targeted at studios, other million dollar a year creative professionals, and (the largest market) relatively rich folks who want to play at being creative professionals. Nothing else makes sense: it's not a computer for enthusiasts, because it's at least 50% overpriced for the market, it's not for developers, as this thread amply illustrates. Consumers are far more likely to buy an iMac than a Mac Pro if they have a desktop at all. The only major market left are people with enough disposable income to buy products because of their branding and because they know it's what the fancy creatives are buying. Buying a Mac Pro will make you feel like a multimillionaire creative - that's the selling point.
It's really the same principle as in digital cameras. Pricey full frame SLRs like the Canon 5D mk.IV are great cameras that are essential to photography professionals, but the vast majority of the market for these cameras is wealthy people who want to buy the expensive model from a recognizable name brand because "it's what the pros use".
Edit: perhaps those who disagree with this could provide their own breakdown of who they think is the target market for these, and how many Apple can expect to sell to each.