One Wikipedia to rule them all

John Battelle notes a study that reports:

In December 2005 ... 2% of the [top] links proposed by Google and 4% of those proposed by Yahoo came from Wikipedia.

Today 27% of Google's results on the first link alone come from Wikipedia, as do 31% of Yahoo's.

Nick Carr once wrote of this trend, saying:

Could it be that, counter to our expectations, the natural dynamic of the web will lead to less diversity in information sources rather than more?

And could it be that Wikipedia will end up being Google's most formidable competitor? After all, if Google simply points you to Wikipedia, why bother with the middleman?

Update: A week later, the NYT reports that Google started testing a "Wikipedia competitor" called Knol. Google VP Udi Manber "said the goal of Knol was to cover all topics, from science to medicine to history, and for the articles to become 'the first thing someone who searches for this topic for the first time will want to read.'"