i noticed no 0.8 version of media-plugins/gst-plugins-libpng is stable on ia64. I am trying to remove all of gstreamer 0.6 series from portage, and ia64 is marked as stable for gst-plugins-libpng-0.6.4 so its blocking.
done
I'm currently testing all 0.8.7 gst-plugins and it seems stable for me. See bug http://bugs.gentoo.org/show_bug.cgi?id=89546 for totem.