Robert_Charlton - 6:31 pm on Sep 23, 2011 (gmt 0)
Terabytes - I took a very quick look, and yes, I'm also seeing several big changes.
Most significantly... I notice, eg, that one page, which had apparently vanished for dupe issues because it had been scraped to death, now returned to its previous #2 spot, beneath the home page, for a competitive single word search... suggesting that perhaps some dupe filters have been adjusted. There's also now a + box, for displaying additional results on the query for that domain.
(This may simply mean, though, another round of testing, as often those extra results are what Google is using to test searcher intent).
On the same site... I'm also seeing some pages that I knew had weak content with iffy linking drop even lower... and pages on which we'd put in some work rise slightly, say from #6 to #4.
Other pages, which had dropped far enough down that I didn't monitor them, are now returned to the top 10. It's unusual to see this much change in a brief period.
This is a site that had for the most part retained its core rankings and had not been hit by any kind of sitewide Panda filter. Most of my other client sites had been pretty stable through all this, and these are the only effects I can report immediately.