Count me in the camp with the OSX fans who still must spend most of my time in 9. At home, it's X for everything except a few games that still want sprockets (go USB Overdrive) for joysticks and such. At work, thought, life revolves around Quark and Photoshop. Quark and Classic don't play well together. This might be one of those areas where an enterprising soul could come from no where to build the next killer app, a publishing program to challenge the king. It would be a tough sell though. Quark users typically hate the company but love the product, and so much depends on what your printers and service bureaus support.
At work, I am the IT guy for the Macs. As soon as practical, I will move the department to OSX. My experiences with it at home have been nothing less than amazing. It took a couple of weeks to get friendly with the dock, but I love it now. Font management was weird until Suitcase 10, but now that I've figured that out, I spend less time hyperventilating about how we'll handle that issue at work.
Every day, some new solution comes along to move the platform a step closer to being ideal for business and home use. That may be the coolest thing about OSX. Computing on a Mac is really exciting again. On Windows, it's same-old-same-old. Everybody knows that innovation in that arena means a few dollars less, a few megahertz more, and whatever Microsoft can find to solidify its monopoly this month.