Get real. 85%? Check your sources. Quark's website claims it has 2 million users worldwide. So given the "25 million Macs" stat that Apple uses, you're looking at just over 8% for desktop publishing on Quark. Maybe your source said 8.5% percent instead of 85%.
Regardless of Quark (which seems to be the only major app yet to port), every OS 9/8/7 user has a simple choice: upgrade to 10, stay at 9, or switch OS. If you stay at 9/8/7, you accept that your apps will eventually stop getting new releases and patches, and you accept that you eventually won't be able to use new products (hardware & software). If you switch OS (Windows/Linux), you will face the same "switch" costs for new hardware/software (though the $$$ values might differ per platform) that you'd face if you went to 10. This is a no-brainer for any individual or company with any foresight, regardless of your budgetary limitations. Pay now under your own control, or pay more later when you're forced to.
Personally, I'm beginning to think that most OS 9 users who are whining about 10 are as lame as the Windows users they chide. Talk about drones stuck with "beige" thinking. Derrick is right when he notes the lack of creativity here. But I disagree with the "need" to unite. Those stubborn fools who want to rot in OS 9, good riddens. Quality supporters, not quantity (a la Windows) is what will best serve the Mac community.