Microsoft has released very quietly, Microsoft Messenger 7 For Mac. I downloaded it, messed around a little bit, and there really is nothing new interface wise except the drop down for status messages. They have added bonjour support though. You can see a bonjour users group in your buddy list now. Here is a photo of it in action!
Also, Twhirl, the popular Twitter client has been updated. Thanks to my buddies on Twitter, i would have never known about it until it prompted me. (Which wouldn’t be for a couple days.) The interface has changed fairly dramatically if you think about how much easier it is to use now. Friends/Followers, Home, Directs, and Replies are all on easy access buttons on the main window now. No more drop down menu. Here is a photo of it in action as well.