It is not well communicated, but you can apparently write your own “tabs”/”panes” for the panel/toolbar found in the Meego Netbook UX. Hopefully this blogpost helps a tiny bit*.
As stated by the libmeego-panel/docs/README in the source tree of mutter-meego there are convenience APIs for GTK+ and Clutter based implementations. But it seems you can also just use the DBUS API, in case you prefer Qt or something else. I found this out by searching though meego.gitorious.org after someone asked on #meego
*Since this should be documented in the platform API, I’ve of course filed a bugreport.