It now supports a NO_GUI build with no Gtk dependencies. While some may consider the GUI a bit uglier, the code is much cleaner (no depreciated widgets, no large lists of linked widgets) and smaller (~700 lines versus 2300) so making the aesthetics nicer should be much easier. There is also a simple GUI API to easy allow for a Qt4 GUI.
The API has been updated to use Mupen options for setting directories, etc.
There are some minor changes in how hi-res textures are handled. Basically hi-res textures are only loaded from disk once per run. This makes it easy to toggle texture replacement during runtime (like one might want to do while working on a pack). To update and change textures, the rom needs to be restarted and textures reloaded.
Some of the toggle SSE code has been changed. Eventually this should prevent calling SSE functions when SSE is unavailable or disabled.