In readying for the GNOME 3.1.4 development release, there's new development builds available for the GNOME Shell and Mutter -- two of the key components of the GNOME 3 desktop.
GNOME Shell 3.1.4 now takes over control of media handling and auto-run from the GNOME Session, has various message tray fixes, improves the Telepathy communication support, multi-monitor fixes, and various other fixes. This new GNOME Shell release can be read about in the mailing list announcement
Red Hat's Owen Taylor has also released an update to the Mutter compositing window manager. Mutter 3.1.4 is slated to carry much better shadow definitions, theme improvements, takes advantage of newer Clutter API functions, and has miscellaneous fixes. Its announcement is here