Last week I tried to improve gmpc performance in the albumview and metadata browser.
I wrote a image-loader that uses async IO to load the image from the hard-disk (and even the internet in the future). Hopefully this will improve performance on large images or many images.
The next step is writing a small pixbuf cache, so we can add neat things like albums in the playlist view.
Zeltak is also working on improved humanity and hicolor theme. Any feedback is welcome (on #gmpc @ irc.freenode.org)