MythTV 0.27.6 is the new point release available this morning, but it's not a feature release, rather just aimed at fixing bugs. MythTV 0.27 itself was released more than two years ago.
The MythTV 0.27.6 change-log can be viewed at MythTV.org.
MythTV 0.28 meanwhile remains under development. The tentative release notes for MythTV 0.28 mention a new web front-end, a major UPnP overhaul, and other changes.