Facebook new privacy and IM features

Facebook is launching an instant messaging tool as well as additional privacy controls, including the ability to create various friends groups with different permissions for each.  TechCrunch's article on the news is most informative.  These features should be rolled out Tuesday night or Wednesday morning, so keep your eyes open!  I am really looking forward to the IM feature, and can see several potential uses for the friends groupings...even for libraries.  I'll keep ruminating on that one until I have enough worth saying :)