The 2.16.0 release is a stable release of GDM with the following new features:

- Minor improvements to SDTLOGIN logic, used on Solaris to drop the Xserver to user permissions for added security.

- Translation updates (Subhransu Behera, \305\275ygimantas Beru\304\215ka, Runa Bhattacharjee, Stanislav Brabec, Abel Cheung, Theppitak Karoonboonyanan, Gabor Kelemen, Duarte Loreto, Jordi Mallach, Jovan Naumovski, Roozbeh Pournader, Josep Puigdemont i Casamaj\303\263, Rajesh Ranjan, Hendrik Richter, Danilo \305\240egan, Mugurel Tudor, Funda Wang, Matic \305\275gur)

- Highlights from the 2.15 release cycle. GDM was enhanced to use giochannel for communication between the daemon and slaves and goption instead of popt. gdmsetup startup performance improved, and the "Options" button usability has been further improved. The following bugs were fixed.
327530 - Ensure login window always has focus.
341619 - No longer save "Failsafe" sessions as user's default login.

Online Documentation - http://www.gnome.org/projects/gdm/
Latest Stable - http://ftp.gnome.org/pub/GNOME/sources/gdm/2.16/
Latest Unstable - http://ftp.gnome.org/pub/GNOME/sources/gdm/2.15/

No RPM this time around BTW. Have fun. A spec file is included though, so you can try:

rpmbuild -ta gdm-whatever.tar.gz