You can do this:
You will be prompted during the installation to choose a display manager. Choose gdm-2.20
sudo apt-get install gdm-2.20
Next edit /etc/gdm/gdm.conf and change any entry of /usr/X11R6/bin/X to /usr/bin/X There are at least 5 instances 1 near the middle and 4 or so near the end of the file. It is good size file. There are other entries youmay wish to uncomment like "AllowGreeterThemeChange" (or such, just keep a look out.)Save the file and reboot. You should be greeted with the old gdm theme and back to the hunky-dory login window configuration utility.
Special thanks to this contributor for filing a bug and work around: http://pitris.info/ubuntu