"You might have noticed a few fancy little changes we've made to your feed tree on the left pane today. You'll like them even more when you learn what's behind the scenes!
- We no longer update the entire left pane when the unread or "kept as new" counts change. Now the counts update in place with a fading yellow indicator. The result is a faster, more pleasant way to cruise through your feeds, especially for those quick on the hotkeys.
- We've decreased the time between automatic updates to your unread counts so you don't have to press the "r" hotkey quite so often."
It also appears to be a different typeface and a slightly 'fancier' look. Some nice ajax touches. This is just on the left navigation pane though - the actual reading pane stays the same. It'd be great if the ajax changes could be applied to the whole screen... maybe they're making the right pane next year's upgrade ;-) (kidding)