Kaiser claims that the source for Doom64EX and PowerslaveEX will be released, "soon", or so he said before the take down order in May. The problem was he had game data in PS. Once a hasher program is added along with a way to get to the genisis data, he might make the new source available, says he wants to.
EDIT: Doom64EX is under the gpl, I assume it's PowerslaveEX or just the KEX engine your concerned with.
It seems that Kaiser has continued his work involving blood on the kex engine. You'll have to scroll down the thread as I cant link directly to the post in question.