No significant feature additions to Dropbox 2.1.4 for iOS, released on April 22, 2013. But there are some solid bug fixes. So it's definitely worth the update for your iPad.
Tip: The interface for reading PDFs in Dropbox is quite good. But if you want more features, such as bookmarking, then use the "Open In" command (icon in upper right corner) and view the document in GoodReader for the iPad.