It was the first time we all watched and socially used media to discuss an event simultaneously. We could Tweet to send people to information sources, load up our observations, even make up a few jokes (Kanye West meets Anne Frank seemed to be the most popular combo).
It was an event of participating, not just of spectating. It was an event of creating, not just of receiving. It was the 21st century equivalent of the O.J. Simpson white Bronco chase, only we could keep our eyes on it and send others our views --- and, of course, the outcome was more positive.
The three hours of live viewing and sharing, followed by the days of declaiming the episode, will set us up for more significant shared experiences in future.