As I posted earlier, Scott has released the source for GIMPShop based on GIMP 2.2.8. Well, we will soon be able to use the said source to actually do stuff very soon. I've been in contact with Dakira, the compiler of the Windows version, and he says the new source should be up within a couple of hours - I'll edit this post with the link when he has it ready.
In the meantime, all my Linux brethern can compile GIMPShop from source. These directions from Suramya should be helpful.
The Latest version of GIMPShop has been ported to Windows by Dakira.