If I were to use Windows 7 or 8 either via Boot Camp or Virtualisation Software on my Mac would my Magic Trackpad still function? If I were to install Windows 7 or 8 either via Boot Camp or Virtualisation Software on my Mac would my Magic Trackpad still function in the Windows environment or is the ability to use gesture control inherent to Mac OS X ?
There is a table showing the features of the Magic Trackpad supported for Windows 7, Windows Vista and Windows XP on the About Apple Magic Trackpad (and 27-inch LED Cinema Display) Update for Windows on the Apple Support site.

http://support.apple.com/kb/ht4273

Windows 8 is not currently supported by BOOTCAMP. Boot Camp 4.0, OS X Lion and Mountain Lion: Frequently asked questions refers:

http://support.apple.com/kb/HT4818#3.1