not a dead project
the gimp painter git http://git.sourceforge.jp/view?p=gimp-p ... ;a=summary was kept in sinc with gimp git, last change was in January (but should be no later changes in gimp involving gimp painter hacked tools)

and Alexia Death was working to port in gimp some functionality of gimp painter, and as you may see from the linked page other gimp developers contributed to make gimp paimnter more compatible with gimp