There was definitely a Pandalisation of my AdSense earnings with 2.1, my AdSense was cut over night, no gradual decrease, simply slashed over night.
Average daily earnings from 6th May 2011 v 1st January to 5th May 52.6%
Average daily ctr for the same dates 64.9% however there has been a notable improvement in September but that could be more due to me blocking attempted image linkers.
I've not had one single day's click volume since 6th May achieve my Jan to May daily average and only ONE day from January to May was at the current average level...Easter Saturday!
For the same periods my average EPC is 101% therefore no reduction in ad click spend.