(1) Search Ads in Search Suggestions:
(2) Improved "navigational query" support:
(3) Search Suggestions even on search results pages:
(4) No estimated count numbers, as you can see from the screen shots above. Here is a screen shot of the old way:
(5) Search suggestions are now personalized based on your search history and other factors:
(6) Google bolds the query words in the search suggestions drop down.
I don't see this feature live yet, but it should be soon.
Forum discussion at WebmasterWorld.