Broken MATE panel
Following an upgrade in Debian Jessie/testing, I was left with no panels at all after logging into the MATE desktop. Running dpkg -s mate-desktop, I saw that MATE had been changed to 1.8 from the previous 1.6 version. My first thought was to try
apt-get install mate-desktop-environment
and it actually did the trick. I’m glad I didn’t need to resort to Gnome Shell yet.