(Not saying it is these but check them out)
Samurize
Rain meter
Windows blinds
Windows 7/vista gadgets
rocketdock (or some other crap)
windows - Lifehacker lifehacker usually talk about stuff like this, just search for simple stuff like "Theme" or "desktop" or something.
But yeah, it actually could be a KDE platform desktop, or an Ubuntu one for that matter, seen it done..
But I dunno, I'd never want my pc to look like that. That looks pretty messy anyways, and un-resourceful.
*That messenger looks like Trillian (Custom skin)