There is good news for Debian Sid users. "The final bits of GNOME 3.4 have landed and if all looks as good as it does now, they should migrate to wheezy in about a week," posts Jordi Mallach on his blog.
He further writes that the move from 3.2 to 3.4 wasn't as "complicated as the previous horrible transition, but still had some complications due to Cogl/Clutter incompatibilities. Other than that, our major problem has been manpower, but this isn't new for many other Debian teams.
He also points out some problems, "We've also seen new incarnations of 'Linux-only technology is now mandatory' which makes our lives a bit more miserable due to kfreebsd-* and hurd-i386, but for now we've still been able to dodge it. It seems wheezy+1 will be fun in that regard though, and we might need to take drastic approaches."
If all goes well without additional problems, the team should be wrapping up the transitions for wheezy with Evolution and friends (currently sitting in experimental), and hopefully GDM 3.4.
He also explains the issues regarding GDM in Debian, "...unfortunately our GDM expert has had little time for Debian lately, but we're confident we'll end up with a GDM in wheezy that is on par with Debian standards."