The first development release of GNOME Boxes was pushed one month ago, but now in the lead-up to GNOME 3.4 stable there is another Boxes release. For those only hearing about GNOME Boxes for the first time, there is detailed information on this virtualization management program on the GNOME Live Wiki.
Boxes is meant to be a simple GNOME3 way of accessing and managing remote (read: Boxes isn't only about virtualization) or virtual machines. It's also meant to be simpler than virt-manager and more targetted at casual Linux desktop users, but some code is shared between the two projects.
Anyhow, in the GNOME Boxes 3.3.3 release are user-interface improvemements, an express installation mode for Microsoft Windows XP, Box creation wizard enhancements, and much more.
More details can be found in this developer's blog post. Below is also a video of GNOME Boxes 3.3.3 in action.