For what it's worth, we run predominantly 10.6.3 and have users using both CS3 and CS4 with no problems. As far as I can tell, Apple didn't screw any pooch here.
As far as SL for prepress work in general, there's no way I would go back. Yeah, it took a little work to reconfigure our old AppleTalk-based printer queues to use IP printing instead, but for me the speed, improvements in search and other refinements to the Finder have been well worth some minor upgrade issues. Honestly, I think my production Mac today is the most stable machine I've ever used. (It's a 3 year old Mac Pro with a double dual cores and 10 GB RAM if anyone's curious.)