Well we have a degree of consensus that it has been happening on brand and exact domain match queries that generate sitelinks. We also have indications that it is probably a deliberate move by Google rather than a bug.
That's kind of disappointing.
Speaking as a user, not as an SEO, Google baffles me. For the queries I search as a leisure user (mostly music-related topics) I have to say (subjectively) that the SERPs I see post Panda are far less immediately satisfactory that they used to be. I seem to spend more time clicking deeper into the results and refining my search terms.
Also as a user, rather than an SEM professional, my perception of Google as a brand is not as favourable as it was, say, 12 or 18 months ago. They seem to specialise in half-assed product launches (phone, Plus, tablet), and they also seem to be tying themselves up in knots with all the changes to their core search product.
With both Panda and these recent SERP changes I kind of hoped it would turn out to be a mistake that would be rolled back to the Google I used to be able to use quickly and easily.
Obviously my objectivity is compromised by awareness I get from my work. I wonder what genuinely objective users think of it all.
I still fail to see how 7 results can be better than 10. Without over-thinking and analysing, it just seems fundamentally stupid from a common sense perspective.