>>It's a truism: ask 10 people here what version of Windows they use and you may receive 10 different answers, many of which will include XP that MS tried to retire years ago.

And a few Win98's and Win 2K's.

I think that depends on the slice of the population you survey.
I'd suspect that most developers are using Win 7 by now, but keep the VM button handy to switch to XP as need be. I'm switching less frequently, but still do it now and then.

In the case of our clients, most are using Win XP for the LAN-based business apps that we support with an occasional Win98, Win2K and Win7 machine here and there.
I've yet to come across a Vista machine, but I suspect that there are some out there.

I've noticed a tightness in the hardware/OS budgets that's not evident in the application software budgets.