@bluemukaki I’m pretty sure that Aperture and Final Cut Pro were actually mostly developed by Apple. They did acquire some applications, but those are lower profile (Logic, Shake, and Motion, I think). In either case, even if I’m wrong about that, it’s clear that Apple actively prefers the slate gray look for their pro-apps (considering that Final Cut is huge for Apple, you’d think they’d redo the interface if they didn’t like it). And they have good reason, in my opinion. I’ve definitely heard creative pros complain that the Mac OS X interface is too distracting when they’re working. I think the pro-app interfaces are an attempt to turn down that distraction.
@ukasaka Aperture has most of the same tie-ins to the OS that iPhoto has. You just have to install it before you see them.
Not that I’m in love with Aperture (as I said above) but I thought I’d clear up some misconceptions.