Earlier quoted context omitted.
They'd have to create a Windows version of Git first, wouldn't they? Then the GUI.
I've been running Git on Windows for several months. I don't see any reason why they can't take advantage of the existing work in that area. http://code.google.com/p/msysgit/downloads/list?can=3
I mean, it's not as if GitHub don't have Windows instructions... http://help.github.com/win-set-up-git/