For example, Wikipedia's list of social networking websites now contains 111 entries; an impressive list, but certainly not all-inclusive. To the credit of Wikipedians, the list is now much better than it was just a few months ago, when it contained only 43 entries, but it is still behind the curve.
Then there is the matter of commercial content. While no one wants to see Wikipedia degenerate into a collection of marketing brochures, the site's prohibition on commercial speech seems to be unclear and unevenly enforced. There are tens of thousands of small businesses with no presence on Wikipedia, yet Oracle (the database company) is listed, as are The Oracle (the shopping mall near London), as well as PeopleSoft, SAP, IBM, and many other corporate giants.
Finally, there is the accuracy of the content itself. To cite just one recent example, Debra Mastaler points out in her post Do You Link Dope or Incestuously Link? on The Link Spiel that Wikipedia's page on link-building methods contains "terminology used to describe outdated , incomplete and irrelevant link methods." She goes on to write that "And yet, when I publicly suggest knowledgeable people with good content should contribute to the Wikipedia, I'm spoken down to, told to read the conflict of interest guidelines and criticized." Ouch. And Debra is by no means alone on this.
When frustration in the user community is combined with the opportunity for astronomical site traffic, competitors are bound to emerge. One such alternative is Freebase, which is still very immature (but does have its own Wikipedia page). Of no doubt more concern to the Wikipedians is Knol, Google's still-in-beta entry into online reference. As Michael Estrin points out, "According to Hitwise, more than half of Wikipedia's traffic comes from Google. While Knol and Wikipedia may not be direct competitors in terms of style, the two do appear to be on a collision course for top billing when it comes to web queries." To put it more bluntly, Wikipedia gets high traffic because it gets great placement on Google searches; what do you suppose is going to happen to the site's search engine position once Google has a competitive offering?
Despite its flaws, Wikipedia isn't going to disappear. But the shine is off, and serious competitors are emerging. Through a combination of success and arrogance (over-zealous article rejection, the use of insidious "no follow" tags, condescension to contributors), the Wikipedians have brought this upon themselves.