On June 23, the new artwork for Debian Wheezy. As described in the mailing lists from the weekly news, the new artwork was sought to be simple and light. Debian users using the repositories Testing o Wheezy you can get this theme by updating the package desktop-base.
Without giving it more thought here are some samples of the new artwork:
Wallpapers:
Grub:
Plymouth:
For the most interested you can consult and get the topic from this link: http://wiki.debian.org/DebianArt/Themes/Joy