From what I hear, the full version should be out for the Mac by now. The Mac version for Duke is equivilant to the Atomic Edition for the Pc. There is a shareware version for both the 68k Mac and the PowerPc Macs. There is also a patch for it, and to even further complicate it MacUser has a special shareware version of it with one more level than the regular version(The link for this version leads to the MacUser page for it since they say that only they can distribute it.).
I don't even have the full version for the Mac, heck, I don't even have a Mac, so don't even think about asking me for it.