There are a lot of behind the scenes changes, but my favorite changes are:
- The new bookmarking system which lets you "star" a page (like gmail) quickly, and then lets you search through your bookmarks and history right from the address bar.
- As you search from the address bar the results get narrow -matching both the URLs and the page titles in your history and favorites. The matching parts are underlined, guiding your eye clearly to why an item is showing up in the search. The results list is uncluttered and much easier to make sense of.