i've rendered out of premiere and encoder with the new os just fine. Though it sure took a lot of crashing for one particular project which i ended up taking the whole thing to the older osx. We decided to not upgrade all the other machines as a result so we have one black sheep here that isn't really being used now...
I'm not sure if these are issues associated with the OSX upgrade
There have been quite a few reports of issues using Snow Loepard. The 'fix' seems to be reverting back.
As Jim points out, there are tons of reports on Snow Leopard not playing nice with much that is Adobe. Word on the "street" is that Apple is working hard on an update for it, and it should be coming about "any day" now. With Apple stock taking off, it seems that they would have the $ to get it out in a hurry.
Here's hoping that they will, and that it will help many Adobe users and quickly.
PS - I hope that Snow Leopard does not become Apple's Vista...