It will hopefully integrate with 3rd party software as well and will the GUI will change from one or multiple hand gestures. Current today screen's do not show how many messages from IM apps you have, correct me if I'm wrong.
Here is a quote that was found from a user in The iPhone Blog.
“The user interface has a plurality of application icons. In response to a first gesture, the GUI changes the appearances of the application icons whose corresponding applications have user-adjustable settings,” the filing explains. “In response to a second gesture on a selected application icon whose appearance is changed, the GUI displays user-adjustable settings of an application that corresponds to the selected application icon. In response to one or more additional gestures, the GUI changes one or more user-adjustable settings of the application that corresponds to the selected application icon.”
I'm not sure about the IM messages. However, a Today theme with the ability to not only add third party apps to the homescreen, but just to be able to change the display PERIOD would be wonderful!