The big news yesterday from the major search engines was the launch of schema.org. This is the search engines uniting to make HTML markup for structured data to be used on the search results display easy and more manageable for webmasters.
This markup language is typically used by search engines to show richer content in the results. Like for recipe results, ratings, reviews, etc.
The full documentation is over here.
Vanessa Fox at Search Engine Land has a very good write up explaining why they are doing this and more importantly do you need to change anything going forward.
The quick answer is if you have already done markups, you won't have to change anything because the search engines will continue to support the old markups. But if you are building out a new site you may want to adopt the new markup schema.