Similar to the overlay you see before you start viewing a stream that is intended for mature audiences, it would be nice to have a button available on channels that leads to a short intro theme for that streamer's channel - could be a theme song, user-submitted/streamer and Twitch-approved clips of the stream before you go to the live stream.

Also, this slot could be used for a short video entry made by the streamer to lay out what their goals are for the duration of the current broadcast, to let viewers know about important announcements, etc.