We’ve covered this topic on the PRO site a number of times in discussing Facebook’s issues. (See here and here, for example) Remember when everyone would go nuts when the word “social” was mentioned and talk about their “social layer?” Their future, and the future for most consumer-facing tech companies, is not social.
It is mobile.
The trend away from desktop and towards mobile will take the eyeballs, and then the ad dollars, subscription fees and in-app payments, with it. It is already happening.
Here is another article that shows that AOL (Yes, they are still around) and Facebook also see it our way.