It seems to me that it is far easier to make the leap from Windows, Linux, UNIX, or BeOS (bless it's little heart) than from "classic" Mac OS to OS X.
I personally can't see the attraction of OS 9, and find it confusing and disorienting when I do have to boot to OS 9 for some reason. That seems to be the rub: "when I have to". Fortunately, I have little reason to leave OS X and, once Emagic Logic Audio is released for OS X, I may never have to again (well, Alpha Centauri plays better in OS 9...).
I understand that a lot of people need OS 9 to get their work done. Either some app isn't OS X ready, or their workflow depends on a long history of OS 9 usage, and can't be (easily) moved to X. I'm guessign this last kind of user will be the hardest to convince.
I agree that Apple needs to do more to encourage this migration away from OS 9. Either with strategic moves like aquiring technology (to make sure that the key app families are covered and supported under OS X), to working with hardware vendors to get drivers out, to making it easy to get OS X into their hands.
The last item suggests that there should have been a more attractive "upgrade" pricing approach to 10.2. Jaguar looks and sounds wonderful, but Apple needs to know that this is the first real release of OS X for many people.
OS X is more of a leap for OS 9 users than us "switchers", it seems. Apple needs to ensure that the pros outweigh the cons. Otherwise, people will stick with what they know works and resist moving to what is (in my not-so-humble opinion) a much superior operating system. Certainly superior to Windows, and (dare I say it) even superior to OS 9.