As Apple gears up to reveal OS X Leopard (among other things) at next month's Worldwide Developers Conference, some people are beginning to wonder precisely which Mac models are going to 'make the Leopard cut'.

What's left discussions on this topic wide open at this point is the fact that no one knows for sure how Apple's going to do it. Will those that run the G3 or even the G4 processor be excluded from the list? Or are the good folks at Apple to decide based on the speed of the machines' processors?

eWeek's David Morgenstern thinks that if the decision is to be processor-based, it's unlikely that Apple will exclude all the G4 and G5 machines, at least not just yet. Apple still does sell computers that run on PowerPC processors; the company's transition to Intel isn't complete yet, which means that there isn't a large enough base for Intel machines for the company to go by. In addition, the last G4 machine, a 14-inch iBook G4, was discontinued just last May. If Apple does choose to go by processors, it's likely that it's the G3 machines that'll be denied a chance to 'get with the program' due to their age; the last G3 model sold was a variant of the iBook that was axed in 2003 (two OSs back).

But Morgenstern also thinks it's possible for Apple to base its decision on video RAM, or VRAM. Many older Macs lack VRAM, so, if Apple goes by a base level of installed video RAM, most (but not all) G3 models and many of the older G4 models, like the Cube, the older PowerBooks and the first few PowerMac G4s could be left by the wayside.

Any ideas? What do you folks think? Hopefully Apple will clear up this issue next month at the WDC.