Originally Posted by ~sHyLoCk~
That's gentoo's default KDE theme. You will find it in the LiveDVD. They recently had a theme contest to decide the artwork. I am not sure about the details of that particular theme but you will find relevant help if you ask this in the gentoo forums.
Damn it, I was really hoping it as going to be a Gnome theme. Oh well, Thank you very much.