Actually, some guy is reverse-engineering the DN3D engine and trying to get it to work... (by "it" I don't mean PPC porting)
Porting shouldn't be ridiculously hard; however, I think the opensource engine is still in its very early stages (read: unplayable)
Here's a link...
It's being done by the same Bruce guy who did a WinCE port of Doom. Obviously, that has nothing to do with DN3D being ported.
And the last update is May 18, 2002... a bit worrying.