While I can't support this with figures, which I'd love to see by the way, my experience working as a consultant at a number of companies, from startups to big media conglomerates in Europe, is that for web, there's definitely a preference for macs, however slight.

It's generally older, more conservative or more back-end focused shops that are on Windows (.NET, Umbraco), but even those often move to macs or want to. Viacom, for example, uses Rails for it's European sites and all developers in the office use macs.

Smaller startups tend to have mac-users for front-end development and a mix of windows/linux/mac for back-end guys.

And of course my experience here on HN gives me the impression that most front-end stuff is mac-centric.

All that said, the big qualifiers are wealth and web. I know quite a few web guys who use windows because they can't afford a mac, and I know many developers who use windows or linux because they don't do front-end web development. But in my world (The Netherlands) the vast majority of web developers use macs, to the point that it's kind of a 'thing' to see a web developer use anything else.

agreed, I haven't seen any states, I am just basing it on my personal experience in the UK. I use Windows in the Day and OSX for personal projects. Wonder where that puts me?