A better question might be: What computer company (electronics company) is focusing on professional artist/photographers?
Apple hasn't been for many years and I can't think of another company right off.
JJJ posted a link to a Sony laptop, has Sony ever focused on the high end any more than Apple? No. They've got tvs, cameras, games and even robots.
I think Apple needs a stripped down version of their product that you can order a la carte. I'm talking more than ram, a few video cards and hard drives. Different screens (matt, glossy), ports, drives (Blue ray), multi battery attachments, off-road/rugged versions. It's also telling that they have yet to update the MacPro desktop. It better be worth the wait. All that said, I've had fewer issues with my mac than I ever had with my PC. Also, the price difference between mac and pc, if you compare Apples to "apples", is very close. Much closer than it's ever been.