In addition, on top of the loss of functionality, the guys at Ubuntu have come up with a very serious and profesionally looking GDM default theme, which obviously didn't do it for everybody. People liking colorful login screens, or the ability to change them every now and then, were frustrated by this situation.
SUFFER NO MORE, FOR GDM2 IS HERE!
GDM2 is a login interface management utility for the new GDM. Among other features, GDM allows for wallpaper customization, autologin option and prompted or userlist login. If you want to give it a try, do the following (instructions specific to Ubuntu 9.10 Karmic Koala):
From the command line, run the following commands:
Just to clarify, the steps above simply import a new PPA, update your repository list and then install the GDM2 application.
sudo add-apt-repository ppa:gdm2setup/gdm2setup sudo apt-get update sudo apt-get install python-gdm2setup
That should do it. You should now see a new menu item labeled "Login (GDM2Setup)" under System > Administration.
Good luck and happy GDM'ing!