I think the whole point is to make a certain subject more accessible and fun for students who are more "attracted" to different topics. May be there is an inner engineer in some english major students and vice versa.
Chat is more of a generic term. The discussions we refer to are content based (right now centered around one hashtag or a Tweet). We will have other contents soon (hint: original content).
We haven't dig too much into optimization yet, it's _almost_ vanilla Meteor with MongoDB.
The hashtags are created by the users, and they automatically rank based on activity, we will have many more interesting ranking algorithms to come.
In my opinion you could have chosen a far better moment to launch, and a far better launch than the current. Don't expect your potential users to start digging for info for themselves (launch content) on a product they don't know and which on first sight is only irc (launch timing: better launched a bit later when you had a killer feature).
To me it is like you are introducing the iphone1 with the same famous talk by jobs, but stopping just before the it is one device killer punch line. Instead you are promisingbthat the 3 devices will become one in the future, with a lot less credit than Apple had at the time.
Lets end with saying good luck. I hope to see a subsequent announcement one day which reaches the FP, telling us you made it :).
