Comment 10 for bug 1257505

@Seb - I guess it's just caused by the current state of ppa & all will be better when released..
$ apt-cache policy gnome-control-center
gnome-control-center:
  Installed: (none)
  Candidate: 1:3.8.6-0ubuntu1+unity
  Version table:
     1:3.8.6-0ubuntu1+unity 0
        500 http://ppa.launchpad.net/ubuntu-desktop/unity-control-center/ubuntu/ trusty/main amd64 Packages
     1:3.6.3-0ubuntu49 0
        500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

That version is not installable due to
 gnome-control-center : Depends: libgoa-1.0-0 (>= 3.7.90) but it is not installable