I am releasing the current SVN code to get some more testing exposure. I have been using the code for a couple of weeks and I am pretty satisfied with how things are working. I'm sure there might be a few bugs mainly due to the size of the changes in the code, but many of my test cases are working well.
The code can be obtained from here:
GTK3 support can be enabled in gnome-mplayer with the --enable-gtk3 flag
passed to configure.