SQL Developer 3.1 EA is now available for download here. Have a look and try out several of the new features introduced as part of this release. We have done a lot of work around adding DBA functionality for RMAN, Datapump and other features and vastly improved Database Diff, Database Copy and Database Export.
In Migration, we've introduced a TeraSQL translator and greatly enhance our Sybase TSQL parse. We've also done a lot of work with insight, including templates for most statements directly from published documentation and added column formatting for SQL*Plus. These are only some of the highlights for this release and we will publish a full list soon.
As usual, you can ask us any questions on the forum or add a feature request. Let us know what you think!