I've been experimenting with re-creating the Windows 7 look and feel in Gtk using CSS. It looks super realistic now that Blur My Shell exists!
Please feel free to download the demo off my github and give it a spin! Also, if anyone would like to help with porting some widgets I'd be very greatful! There is quite a lot that I haven't yet managed to style.
Oh, I think that would actually be quite easy to implement. I have full control over how the windows look because they're decorated on the client-side with a custom Gtk widget library.
I'd certainly be interested in using it if you can do it, would be funny to confuse my coworkers on my next pair programming session