On Monday 5th November Google released Panda update #21 – the first new iteration for 5 weeks. Google confirmed this update on Tuesday with a Tweet:
The latest Panda refresh is reported to impact about 0.4% of general queries and 1.1% of English searches in the US.
Over at the Webmasterworld forums there is an interesting thread with several people suggesting this was a roll back of #20 and that the quality of the SERPs have been negatively affected. Little change has been reported in the UK SERPs with only the US seeing much movement as initially reported by Danny Sullivan.