I had a similar thought the other day when watching Wilco's Ashes of American Flags DVDs. Musicians play the same songs for 5, 10, 30 or more years. They jazz them up with modified arrangements and new members but the basic structure is the same. The incongruity with the audience comes often when the musician attempts to push new material forward while the audience desires to hear the old stuff. The way to make it new is to totally destruct and reconstruct the song. Why isn't the audience doing that? It seems like over time we should see concerts trend towards more participative events with different players in every city. As you say, it's the event that replaces/supplements the media. New events too, perhaps.

Not entirely related, but as an example as a "new event", how about a cruise + conference? Social Fresh Cruise, http://socialfresh.com/cruise/

I've had a feeling lately that there are more conferences than there used to be; perhaps conference commodization will force conference style and format innovation?

Couple conferences I have found intriguing lately: The Feast http://www.feastongood.com/ and Overlap http://theoverlap.org/2009/