Penguin 24th April
Googles latest update the Penguin update launched on April 24. It was a change to Google’s search results that was designed to remove pages that have been spamming Google. Spamming in this case is where people do things like “keyword stuffing”, “hiding text” or “cloaking” that violate Google’s guidelines.
Panda 3.5 19th April
On the 19th an update of the Panda algorithm was launched. Panda is an algorithm designed to promote higher quality pages over lower quality sites.
Parked Domains Problem April 17th
Google also made a rare admission that it made a mistake – on the 17th April they had a problem that was incorrectly identifying sites as parked domains. A parked domain is one that you own but has no content apart from a holding page.
This is an executive summary of a longer post at search engine land here