Obviosly several billion websites aren't just going to vanish, but does big business concentrate more on their website or more on their facebook page?
I'm a web developer, have been for about 15 years. And I have been noticing how strong the social marketing movement has become. It seems the very best way to directly communicate with customers is via facebook and twitter, with the nod to facebook as the leader. What I find interesting is integrating social networking tools into a website isn't overly difficult, especially for larger companies that can afford a few good programmers. But they don't do it. Not only is it easier to just use facebook, it makes more sense from a profit standpoint. A company would be remiss NOT to have a facebook page. probably 50% of the information considered "news" about an organization would be disseminated quicker via facebook and twitter than by it's homepage.
And this model really works for ALL websites. News, Ecommerce, education etc.
I used to have a facebook page, and dropped it because it ate up so much of my time. It can be addicting, kinda like Redszone except with farms.