Not intending to start a Mac vs PC debate, I'd still like to point out that the 30% market share Michael appoints to the Mac in his "Aperture" article is quite far from my observations.
"And while the Mac has less than 5% of the worldwide personal computer market, it apparently owns about 30% of the marketplace among creative professionals in the video, graphic arts, animation, photographic and music segments of the marketplace."
Having worked in design & advertising in Los Angeles for the last 17 years, I can readily attest that the vast majority of "Creative Pros" are on the Mac.
-For design & advertising for print, 100% of the shops I've encountered are Macs-based.
-Of the half dozen film poster & movie trailer shops I know of, all are Mac-based though some are augmented with a few pcs for Avid editing.
-There are three cgi/intersticial/title companies I've worked with and they are all Mac based (though a few years back some were using SGI work-stations for certain 3D applications). Most use Avid, though many have started using Final Cut since it's ability to edit/export HD a few years back.
-Sound recording I would say from my limited observations is probably less. Yet, from reading the studio profiles in places like Mix Magazine, it appears that most (70%??) artists with project studios at home (Moby), are Mac based and most are using Pro Tools over Logic. Many "big" studios still use dedicated recording/mixing consoles.
-As for commercial photography? Well Michael, that's your cup o' tea. Of the product photographers I've used in the past, I'd say 70-80% are on a Mac. What have you seen?
Apple has been a great platform for me over the years, especially with its consistency in color between applications and output, not to mention the ease of use it has over all the pcs I've had to wrangle with. I just think it deserves the credit its due.