I've been trying out Gnome 3.4 on a Live USB (available from the link in my previous post).
The most exciting new feature for me in the new version is the support for both Windows Live Messaging and Facebook chat in Empathy. The only times I've been embarrassed to be using Linux have been when a friend or relative of my wife has wanted a video chat, and I've been unable to set it up. I wasn't able to try out video chat, but I certainly hope it works.
The most interesting development in Gnome itself for me is the new look for Gnome applications, which does away with the title and menu bar, and adds a new application menu in the panel.
The stock Gnome web browser Epiphany has been redesigned to comply with this new look, and it does look very good, and it makes the best use of vertical screen space. I hope more Gnome applications adopt this new look in the future.
Epiphany looks great and renders pages well, but it lacks a spell checker, and the as-block add doesn't seem to be available in Gnome 3.4, which means I'll probably be using Firefox. Fortunately, it looks like Firefox is going to adopt the new application look in a forthcoming version.
There are many other improvements in Gnome 3.4 that are detailed in the release notes, all of which make me look forward to seeing it in Debian Wheezy.