Does Find my Mac work if you boot into Windows on BootCamp? If I have Find my Mac set up and Bootcamp is installed as well, will my computer be trackable when I'm in Windows?

What happens if a thief steals my computer and remains in Windows all the time, will I ever be able to track the laptop?
No. The service requires you to be running OS X (Lion specifically) and to have a recovery partition installed (created by Lion during installation). If you attempt to log into iCloud.com to find it's location, it will simply be listed as offline or unavailable.