Hey Fred,
We held off on releasing the four-way conference demo because it functions properly only in Chrome Canary... and even so it will often lead to an 'Oh Snap!'.
In the demo itself, each person does see all other participants so it truly is a conference call. Each participant has a peer connection to all other participants.
As you can imagine, this required each participant to have a more modern computer capable of encoding and decoding multiple simultaneous streams. The real challenge was bandwidth related. Prior to Chrome 24, there was no way to limit the bandwidth of a video stream.
It was a cool demonstration, but not really usable by the masses.
Rod Apeldoorn, Priologic Software Inc.