There is so much stuff out there but not a lot of "school" themes.
Here are some collections of animated backgrounds and Virtual Sets for green screen work, pretty cool
http://www.3dvideobackgrounds.com/
http://www.virtualset.com/
http://www.cg4tv.com/virtual-set
http://www.virtualsetbackgrounds.com/
http://www.virtualsetworks.com/Products ... etPack.htm
I'm still looking