Many of the ebuilds in xfce-extra depended on xfce-base/xfce4-base, which is not correct. Most only depend of xfce-base/xfce4-panel, while xfce4-artwork is just a set of backgrounds (so I put a depend of xfce-base/xfdesktop in it) and xfce4-xmms and xfce4-xmms-controller should also have a dependency of media-sound/xmms. Here are the updated ebuilds, using only the latest versions. I suggest they be used as the same version, but I don't know if they'll need an extra ebuild version at the end to reflect the change.
Created attachment 41867 [details] xfce-extra/xfce4-artwork-0.0.4.ebuild
Created attachment 41868 [details] xfce-extra/xfce4-battery-0.2.0.ebuild
Created attachment 41869 [details] xfce-extra/xfce4-clipman-0.4.1.ebuild
Created attachment 41871 [details] xfce-extra/xfce4-cpugraph-0.2.2.ebuild
Created attachment 41872 [details] xfce-extra/xfce4-datetime-0.3.1.ebuild
Created attachment 41873 [details] xfce-extra/xfce4-diskperf-1.5.ebuild
Created attachment 41875 [details] xfce-extra/xfce4-fsguard-0.2.0.ebuild
Created attachment 41876 [details] xfce-extra/xfce4-genmon/xfce4-genmon-1.0.ebuild
Created attachment 41877 [details] xfce-extra/xfce4-menueditor-1.05.ebuild
Created attachment 41878 [details] xfce-extra/xfce4-minicmd-0.2.0.ebuild
Created attachment 41880 [details] xfce-extra/xfce4-mixer-4.0.6.ebuild
Created attachment 41881 [details] xfce-extra/xfce4-netload-0.2.3.ebuild
Created attachment 41882 [details] xfce-extra/xfce4-notes-0.9.7.ebuild
Created attachment 41883 [details] xfce-extra/xfce4-showdesktop-0.3.0.ebuild
Created attachment 41884 [details] xfce-extra/xfce4-taskbar-0.1.0.ebuild
Created attachment 41885 [details] xfce-extra/xfce4-trigger-launcher-4.1.90.ebuild
Created attachment 41886 [details] xfce-extra/xfce4-weather-0.3.9.1.ebuild
Created attachment 41887 [details] xfce-extra/xfce4-windowlist-0.1.0.ebuild
Created attachment 41888 [details] xfce-extra/xfce4-xkb-0.3.2.ebuild
Created attachment 41889 [details] xfce-extra/xfce4-xmms-0.1.1.ebuild
Created attachment 41890 [details] xfce-extra/xfce4-xmms-controller-1.4.3.ebuild
I'm working on a different route, making base just the core libs and deps needed for all Xfce4 progs.
OK, Brad, thanks for clarifying and coming up with a good solution. If you need any help, let me know; I'd be glad to help get the ebuilds out to all and sundry.