xfce4-mixer's ebuild has a dependency on media-libs/gst-plugins-base:0.10. It's the only thing on my system still requiring gstreamer 0.1x, all other builds, including media-video/parole, which is xfce's recommended media player, are already at gstreamer 1.x. Can xfce4-mixer's ebuild changed to gstreamer 1.x or does this require upstream changes?
http://git.xfce.org/apps/xfce4-mixer/tree/configure.ac.in , Line 99 No work has been done in http://bugzilla.xfce.org/ or anywhere for 1.0 support for xfce4-mixer You can write a patch and submit it to http://bugzilla.xfce.org/