As you know, Microsoft bringing new Windows Live Office in its Wave 4 release, alongwith Office Web Apps to Windows Live Groups. When you first login or create a new Group, you’re presented with following screen:
Note the centre of the pic reads “A Microsoft OneNote notebook is a great way to collaborate with your group online.” This’s a new feature in Live Groups which allows people in your group to collaborate and work on the same “OneNote notebook”. Also, in Groups you can “pin your notebooks” to “Recent” menu on the left, as well as the ability to view group e-mail history. Besides Live Groups now supports up to 40 people for Messenger Group conversations.