Hi list,
I migrated my old GtkBuilder-based LightDM greeter to LightDM 0.9.x APIs.
Now it works well again with the latest LightDM.
It's still GTK+ 2 based. Migration to gtk3 will begin along with other LXDE components later.

The source code is here:
git://lxde.git.sourceforge.net/gitroot/lxde/ldm-gtk-builder-greeter

Main features:
1. Highly themable and much more flexible than the gtk greeter built into lightdm.
2. Works with gtk2 (so we don't need gtk3 for the login manager)
3. Possible to port old gdm themes to this.

Things don't work:
1. Language selection feature is REMOVED from LightDM, so there is no way to support this anymore. We're still discuss with upstream authors about this regression.
2. The themes cannot be edited with Glade when GTK+ 3 is used.

Please take some time to test if the new greeter works for you. Thanks.
I think is a nice alternative to the built-in one provided by LightDM.