I saw this from Kottke, and it is pretty interesting. 

Ostensibly, this particular research was supposed to show whether blogs or "traditional media" was more popular, with the measuring stick being Google mentions. 

But take a look at the results.

Wikipedia is ostensibly the winner here, with wikipedia articles being in the top 4 more often than not.

As this continues, Wikipedia looks to be the default place for articles on any aspect of the world.