* Auto-complete for the nick names in the stream.
* Optional sound-notification when you get a private message — not everybody
  is sitting and staring at the same site all the time.
* No batching. The stream should show 20 last messages and load more when a
  user scrolls to the bottom of it.
* Personal stream and the Site Stream should be on the same view, no reload
  should be required. It's just the matter of switching (tabs, maybe?).