There's already been numerous advancements in the road to GNOME 3.4, but for the 3.3.3 release of the GNOME Shell and for the Mutter compositing window manager there isn't too much to get excited about.
The Mutter 3.3.3 release announcement on the mailing list mentions new key-bindings for tiling to left or right as perhaps the leading advancements, but there's also miscellaneous bug-fixes, support for another GTK+ hint, a multi-monitor fix, and some other work items.
As mentioned in the other release announcement for the GNOME Shell, this latest release carries a bit more changes. There's some small improvements as part of the GNOME Live "Every Detail Matters" initiative and various other subtle enhancements.
The next GNOME 3.4 development release is 3.3.4, which is due in mid-January. GNOME 3.4 final is expected on the 28th of March. See the other GNOME 3.4 articles to learn about other changes to this lately controversial desktop environment.