Today's a big day for us here in MacBU: Messenger:Mac v8, which brings audio and video support to personal users of Messenger, is now in public beta. You can download it from Mactopia. One of my colleagues has written a blog post giving lots of details about it over on Mac Mojo, so head over there to learn more.
Personally, I've been using internal builds of Messenger v8 for months, and it's been quite nice. I've got friends and family scattered all over the world, and being able to do video chats in Messenger helps keep us connected.