Twitter and Facebook focus their experiences on the presentation of real-time streams of information showing ‘what a person is doing’ at any given period in time. That being said, it seems that these streams are swiftly overflowing and becoming floods.
On Twitter, for instance, if you follow folks like Scoble, or Owyang, you get TONS of updates. While you may even enjoy those updates, the interface is not particularly conducive to helping you manage through all that information. While Facebook offers much better controls to manage the visualization of your steams via filters, it isn’t much better. In particular, Facebook is pretty bad because applications tend to quickly use (abuse) the stream so it is filled with junk. And God forbid you have over 400 friends/followed folks in either FB, or Twitter – you are in hell.
The winner of the battle for your activity stream attention will provide the best interface for QUICKLY transforming this flood of information into useful and management streams. If they don’t, both are going to lose some serious attention from users.