We just published a first release candidate for the next major version 1.4 which has now been in development for quite a while. Although the new responsive Elastic skin is now functional and feature complete, it still lacks the final brush-up to make it shine. We have now finally found a volunteer to work on this and once completed, a second release candidate will follow.
For now you're all invited to give the new 1.4 version another test run. Besides the responsive theme it comes with lots of new features and improvements since the beta release. Check the Changelog  for a complete list of changes.
I'm using 1.4b for a while now (and did not encounter anything I considered a bug) - is there a specific upgrade path I should follow, or should it be sufficient to just overwrite the $INSTALL location with the new files?