It seems to me that Facebook has always been stuck with a damned lot: to make their product profitable, they have make their product worse. This is exactly the problem with "social" games. These games are lousy exactly because the lousy features make them money. With the direction that Facebook is going, it seems to be a service where users volunteer to receive spam. I do not think any company in this position is setup for long-term success.

On a philosophical note, I have always felt that Facebook is just a slot machine company. They make a fancy box that takes advantage of the weaknesses of the human brain (obsession with novelty, gossip, and visual stimulus) to keep users doing an activity for much longer than required to get the benefit of that activity. I could be radical and say that I think Facebook delivers no value to its customers and that most people end up actively regretting the time they spend on Facebook (I think it is uncontroversial to say that no one goes to bed wishing he had spent more of his day on Facebook), however there is always someone with a story about reuniting with a long-lost elementary school friend due to Facebook. Nonetheless, even if this value does exist, in no way does it justify the amount of time most Facebook users spend on the site nor does it describe the majority of user activity. This is not to say that Facebook is doomed any more than Las Vegas is doomed, but maybe people will wise up and be more careful about how they spend their time...

A bit of anecdote: I have noticed people on reddit commenting that they now use reddit more than Facebook as all the good content on Facebook is just copied from reddit. If reddit had some kind of social interface, it might move aggressively into this market.