Here's how it works, in my industry at least. You provide details of your workflow to a company that insures completion of the overall production. As part of this, you agree to use the same version of the tools throughout the job, and you don't change midproject. You never use betas in a live project, but other than that at no point are they concerned with whether you are using up-to-date tools or tried-and-tested tools. In between projects, you are free to upgrade the the most recent, and why wouldn't you? You can do a test yourself to see if your tools work, and if you're sensible you have CCC'd your old installation.
Well guess what, 10.7.0 is not beta software. Why are you happy to go straight with 10.7.1? Don't you want to wait until that has been tested, to see whether it has introduced new problems? In fact, now that Snow Leopard has evidently been perfected, perhaps it's finally time to make that leap from 10.5 to 10.6?
This whole thing about people thinking their work is too important to use new software, and that somehow other fools need to test first is just people trying to make themselves sound important. In the real world, we update, but take precautions.
If you ask me, if you aren't able to verify that your tools work for you, have contingencies, and use the latest tools at your disposal, then I have doubts about your professionalism, and I still wait with interest to here some concrete examples.