In the film industry, over 90% of box office sales can be attributed to one of six publishers: Sony/Columbia, 20th Century-Fox, Buena Vista, Warner Bros., Paramount, and Universal. It took less than fifty years for these companies to become the unshakeable kings of the hill.
It happens in every industry. As business gets bigger and more expensive, companies merge and consolidate to simultaneously improve their own potentials and reduce competition. Anti-monopoly laws were created to prevent competition from being eliminated completely (many of the major oil companies in the USA are the result of one giant company, Standard Oil, being forcibly fragmented).
It's happening in the game industry. Ultimately, fewer than ten, perhaps fewer than five, publishers will control almost all of game publishing.
I think we've just witnessed the formation of one of those giants.