The big news from yesterday was that Google is updating social search to be more deeply integrated into the search result. The specifics include:
(1) Social Search results show up directly in the search results and no longer at the bottom of the search results.
(2) The results with social elements now show more comprehensive notes for links people have shared on Twitter and other sites.
(3) More controls on what you share privately and publicly.
Social Search Results Now (or coming soon):
Social Search Results Before (bottom BETA only):
For more information, see this Google Help document or Search Engine Land and here is an updated video from Google:
Forum discussion at Google Web Search Help, WebmasterWorld, Google Blogoscoped Forums and DigitalPoint Forums.