In case you missed it: JoomlaPraise released their new AdminPraise Lite template last week. And it's all free, all GPL!
The Fastest Joomla! Admin Template ever
AdminPraise Lite is a super lightweight Joomla! administrator panel template. Intelligent shortcuts, logical placement, and customization combine to bring you a totally optimized Joomla! experience.
Some people doesn't even know that there are back-end templates for Joomla available out there. Actually, they are as easy to install as the front-end templates.