The latest insight in to Google changes has been released on the Google blog – Search quality highlights: 50 changes for March
Synonyms again appear to be the biggest change that effects organic search and again more talk about anchor text used in links.
This ties in a bit with some SEO experiments I am running which appear to show more importance being given to itemprops.
Haven’t taken in all it says yet, will re-read it again this evening.
SEO Tips