Dunno if it's still true, but some of the pro photo shop reps I dealt with said it was easier to get proper colour matching with standard Mac laptops and Mac displays, if we're talking mainstream priced machines. Then again, Apple's Cinema Displays aren't exactly "mainstream priced", and the same reps sold a lot of Windows machines too, and got proper colour matching just fine. I guess they only sell very specific Windows configurations that they know will work with their usual products.
Final Cut Studio is not THE standard, but is one of the standards. So with Final Cut Studio you have half the industry buying just MacBook Pros, iMacs, and Mac Pros. Then you got 1 or 2 Windows standards using a mix of bazillion other Windows machines. So, in terms of brand recognizability, Apple is #1. It certainly doesn't hurt that much of the older equipment is built around Firewire, and Apple invented Firewire (and won an Emmy for it).
P.S. It's too bad Apple screwed Firewire over so badly, by charging so much for the royalties. I'm looking for a Firewire 800 hub, and they are very, very hard to find. And the few that exist are $$$. I'm tempted to just scrap all my Firewire enclosures and just stick with USB 2, and use my lone FW 800 port for the one FW 800 device I really want it for.