After installing a recent batch of updates in Ubuntu 11.10 I booted back up to find a surprise waiting for me: the new LightDM login screen enabled by default:
Note that the above screenshot is not entirely representative: the password input box is missing, as is the panel to the top right of the screen housing ‘Shut down’, ‘Restart’ etc.
The previous ‘testing’ version of the greeter saw the user wallpaper match that of the account (so if I had yellow dots as my wallpaper selecting my account in the greeter would change the wallpaper to yellow dots). From my brief poke around with it that feature seems to be missing for now.
As with everything developmental what you see above is not necessarily indicative of what you’ll find in Ubuntu 11.10 come October.