Was there an other tweak from 31 May to 1 June? We fell off another 20%. If Cutts says, they want to bring up more quality pages, does he mean small pages with nearly no content and many adsense on it?
Allmost all of the places up to 20 are price searching and comparing sites. It seems like goog tweaked it to have much incoming links and have much outgoing links but have less inner links.
I can remember that this was the same case when they startet with big daddy. Suddenly pages with no content ruled and price comparing site were all over the place. It took about 3 month for google to get it right. Hope it will be the same this time.