What you see here folks is a Windows 7 desktop theme developed by Flickr user David Molina. Ice Cream Sandwich is pretty darn good looking, and David wanted to bring some of that to his desktop PC.
It's not the simplest implementation, and there's quite a few different components involved. The end result though is definitely worth it, and a surprisingly accurate representation of ICS on your PC. Full instructions can be found by hitting the source link below.