The main new feature is the ability to create submenus for boards which will appear in the Arduino IDE.
Arduino 1.5 or higher required for menus.
The new version is still compatible with older Arduino IDEs, except that no menus can be specified for these versions.
Beyond that, some bugs were fixed and board images from the Launchpad family were added (thanks to Rei Vilo).
BOARDS.TXT editor is now compatible with Windows XP, Vista, Win7 and Win8 (x86 and x64).
Source code
If you are interested in the source code, write me a mail:
Heinz.Kessler -at- web.de