Hi Ryuno-Ki, i filled a bug report in order to submit package on repos just a few weeks ago.
You find those packages but searching on packages.sabayon.org results for "mate-applet" remains the same:
Applets for the MATE Desktop and Panel
binary → standard → sabayon-weekly → armv7l → 5 | revision: 0 | date: 2013-05-22
This is for ARM architecture, not x86 or AMD64.https://bugs.sabayon.org/show_bug.cgi?id=4247
Above is my request on bugs site, maybe you could comment on it to not duplicate same issue.