Hi,
We're currently offering x86 users (who are the priority target of the project) the choice between a vanilla Apple XNU kernel, and a Voodoo XNU kernel in the PureDarwin builds that are available, if I remember correctly. Officially, we're not focussing on PowerPC support - although I don't see why an interested person (such as yourself) couldn't attempt to shoehorn in support using old code, or otherwise attempt a brand new port for contemporary machines.
That said, I'm certainly intrigued by your claims, and I look forward to seeing what you come up with.
Tyson.