That's a talk that Wikipedia founder and Wikia Owner, Jimmy Wales, will be giving at the next Free Culture @ NYU Series on Wednesday, January 31st. I'll be there, for sure.
Tim O'Reilly had a lot to say about Wikipedia at Google's Un-bound event, including its comparison to Britannica, in terms of relevance (imagine on a graph Wikipedia on a constant rise, vs. Britannica which is literally, flatlined).
This (via Laura) is Mr. O'Reilly explaining a chart of activity representing the evolution of an entry in Wikipedia, based on the number of changes, edits, and additions [this happens to be a depiction of the Wikipedia entry for Evolution]:
Tim O'Reilly at Google's Un-bound conference in NYC (1/18/07)
There's a reason Wikipedia is one of the world's most influential brands (right behind Google and Apple, and hand-in-hand with You Tube) ... and it has everything to do with free culture.