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These aren't tiny changes on a few of the sites. We are talking ranging from 6 to 0 for established sites. None of the 200 sites are even close to stable across the 5 hand checks we did.
I assume then that PR is now "flexible" by DC instead of confirming that myself, I'm just going to be lazy and throw this out there and see if the rest of you see it too.
This was easy for me to check, as I went from a dynamic site to a static looking site (with URL rewrites) and my second tier internal pages have a PR of 0 or 3.
All I can figure, is that Google got so wrapped up in BIG Daddy, they aborted the PR update before it could propagate to all the datacenters.
It would be nice if Google could finish the Toolbar PR update, now that Big Daddy has been rolled out.