i just noticed no 0.8 version of media-plugins/gst-plugins-libpng is stable on mips. sorry i should have spotted it, with the gst-plugins-gnomevfs one. I am trying to remove all of gstreamer 0.6 series from portage, and mips is marked as stable for gst-plugins-libpng-0.6.4 so its blocking.
0.8.7 keyworded stable