I originally thought that you couldn't use the Windows on Xbox, but that isn't true.
I don't think there have been any changes to the hardware or driver support in the OS. There's an irritating little service that runs after you install the drivers. It seems to be an auto-update thing.
I have the wired controller for Windows and the Wireless one. I've used the wireless on both my xbox and my pc. The only thing to note is that you'll need to have the device "discover" it's host when you want to switch. they develop an affinity for a particular PC or console. You reset it using a little button that (if my memory serves me correctly) is in the battery compartment.
No real insights from me, though. I'd definately recommend the wireless version. The USB-based transceiver supports up to 4 countrollers, I think.
If you can get a cheap wired controller for Windows, pick one up. It's handy for those times when you
want to throw your laptop into your backpack and head over to a Wi-Fi spot to do some dev work. (Less to carry. No worries about the battery life.)
-- joe
There are 10 kinds of people in this world -- Those that can count in binary, and those that can't.