The latest beta build of Dropbox for Mac brings an entirely new menubar menu UI. Instead of the typical black words on white background, the latest build has an entirely custom interface, much like that of apps like Fantastical. And the design looks awesome.
The one bummer: the new menu is not optimized for the Retina MacBook Pro (although the new menubar icon is) which makes the whole thing look fuzzy and out of focus. Which is never a good thing.
As a side note, you actually can still access the old, blander, menu by holding down "Control" when you click the Dropbox menubar icon.
Also, this latest version is still only in beta and probably won't be released to the public as a final version for at least a few more weeks. Of course, being a geek, you probably want it now, so go grab the beta download from the Dropbox forums.
Overall, this latest version of Dropbox is a much needed update to an app's design that was starting to become a little stagnant.