The main new feature is a way to share documents that are attached to publication posts. Further, you can also have thumbnails (magnified by mouseover) of the document displayed in publication lists. Therefor you've got a new set of options in TYPO3's backend to select your preferred way to display your publications.
Another new feature is the possibility to sort publications by title, publication type, and authors. To setup the advanced sorting options we have created a new own tab for sorting and ordering.
You can download BibSonomy CSL extension from the TYPO3 repository: http://typo3.org/extensions/repository/view/ext_bibsonomy_csl
If you interested in the source code you can visit the development repository on Bitbucket at https://bitbucket.org/bibsonomy/bibsonomy-typo3-csl.