Comment 4 for bug 775369

I guess I should respond eventually!

Upgrade does actually remove xscreensaver (the package is gone, the binary is gone, it's gone.), and replaces with it gnome-screensaver.

The xscreensaver preferences stored in ~/.xscreensaver are still there, and when gnome-screensaver is (again) removed and xscreensaver (again) installed, everything is back to where it should be.

Like I said, not a showstopper bug, but awfully annoying to someone who hates gnome-screensaver as much as I do. In fact, it caused me to delay upgrading for probably 3-4 months a while ago, since I wasn't as familiar with Linux, and wasn't sure how hard it would be for me to get xscreensaver back after upgrade.

The whole idea of update-manager is to make updating/upgrading easy, and this threw a wrench in that process for me.