Patrick are you saying that in your opinion it is going to be 64 bit only? I think that it would be a good idea for apple to have it exclusive on 64bit PPC970, why spend time and money on developing basically 2 OS's. That way developers can finnish there 32bit apps and then focus on the future which is 64 bit. The 32 bit apps will run fine on 64bit OS the processor can run them.
As per recent news that the old iPods can't run software version 2.0, I can see that Panther will only run on new powermacs and xserves, epescially when only high end users will reap the benifits of a 64 bit OS. There is no way that they don't make a 64 version of pather, there is just no way. I can however see them not making a 32 bit version. And as for combining them together, when they switched fromt the 803 to the 804, around OS 8, they needed to put old code so that the OS could support older hardware. With every update the OS would seem to get faster, and by the time of OS 9.2 it was really fast. This was becuase they dropped the old code, not becuase they optimized it. I would hate to see apple make the same mistake again, especially when IMHO (opening up the opertunity to flame) OS X is pretty slow already.
-Laz