I find this article confusing. The first example given to support a "web is dominated by big players" is the recent failure of bloglines and migration to Google Reader. But RSS feeds are all about centrifugal force! The vast majority of my feeds are full of links to all sorts of random destinations on the web that I wouldn't have found out about otherwise.
As for wikipedia... encyclopedias are not the key feature of a bookstore. Wikipedia may have the lock on answering "What is X?" on the web -- but the web is (obviously?) about far more than that.