I like the fact that "y8c616" is basing all of this information on just one man, a lecturer at his college. Okay so he's ex-industry, that accounts for something... but then I suppose if someone in this thread is current-industry and told you they used PC's/Windows, and they know of other studios who use the same... that'd kinda cancel out your third-party knowledge, no?
A lot of places use macs, a lot of places use PC's. It's already been mentioned but this whole bollocks about "Macs are better for creative-ness" is just... well, the afore-mentioned bollocks to be quite frank. I'm a 3D artist and it's safe to say my job, and a lot of the people I work with are in a "very creative" industry. There isn't a single Mac in our studio. I'm not however, about to get into why we don't use macs, or even why we prefer PC's... i'm just another individual coming to you as a professional, letting you know that I, and thousands of others in the same boat as me, use PC's.
On a personal note though, I do believe there are more people using Macs just because they're Macs, than there are people using them because it's better catered to their profession.