After unmerging control-center, symlinks remain to nonexistent files: lrwxrwxrwx 1 root root 19 Mar 31 21:29 /usr/lib/libcapplet.so -> libcapplet.so.0.0.0 lrwxrwxrwx 1 root root 19 Mar 31 21:29 /usr/lib/libcapplet.so.0 -> libcapplet.so.0.0.0
Out of ldconfig man page: ldconfig creates the necessary links and cache to the most recent shared libraries... It is thus possible that you will have symlinks in /lib and /usr/lib that do not belong to a ebuild. I am marking this as invalid.
Last time I checked, the control-center package itself contained the symlinks. Additionally, any package that adds or removes shared libraries should call ldconfig* in its postinst. * or its equivalent.