Hey folks!
I think it could be a good point to make some kind of "challenges". Things like algorithms and puzzles (I tried that last week and I think it has had a good acceptance), but also kind of cool challenges. For instance: encourage people to get a certain level in XBOX Live Gamertag, or explain the most strange situation in which technology has helped them.
I know it is broad, but I think it combines some basic points of the Channel 8's philosophy: 1st, all those things are content created by student; 2nd, it combines didactical content (such as algorithms) with enthusiast content (gaming, cool stories) and 3rd, thinking about it as a challenge (I have no idea about what can we offer as prizes though) we are encouraging people to comment, comment, comment... and create community 
My two cents!