We have the new gnome-shell_3.6.1-3ubuntu1 in RR repo now.
That flavour is build against the new libcogl11 (instead of libcogl9).
Also new libclutter-1.0-0 (1.12.2-0ubuntu1) is build against libcogl11,
like libclutter-gtk-1.0-0 (1.4.0-1) too.
Well, one would expect that there were the related new mutter too.
However, the new version (3.6.1-1ubuntu1), which is build against libcogl11,
bears the new name libmutter0a (instead of libmutter0).
So it cannot be installed and the old lincogl9 thus cannot be removed.
One more time:
we need the package libmutter0, built against libcogl11 or a new gnome-shell built against libmutter0a.