peterzakin

the first two angles make sense. Facebook is what facebook is because of the culture around it. Culture changes with the emergence of new technologies/features. So i would think that the most probable scenario for a facebook death involves new companies that make better use of emerging technologies, e.g. geolocation. And i happen to believe that if facebook drops the ball on geolocation, and geolocation services see a major increase in popularity, we may see the birth of a competitive social graph. That is a real possibility.

As for your third angle, I think there is room for a niche-facebook that could be crazy profitable--but i don't see a niche social network taking over the social graph. that seems relatively far-fetched.

People may end up preferring liking to digging (though who knows at this point), but when it comes to actively looking for interesting content, digg's still got something to hang onto. It begs the question, however, whether facebook will ever make an attempt to organize all of the outside links users promote so that such content becomes discoverable by topic and not just incidental lines on the newsfeed?

That facebook's concern for its users' privacy is secondary to more "practical" matters has been clear for some time now--though perhaps most evident with Zuckerberg's memorable, "privacy can no longer be an expectation." And this recognition is not limited to HN-types and "internet gurus." General users, college students especially, also realize this and so a pattern has developed in which younger users (speaking from the perspective of a college student) exercise a degree of caution (probably less than sufficient) while in college and then upon entry into the workforce, remove the wall, photos from their profile and thus their facebook profiles becomes little more than a prettier linkedin. If this pattern reflects more than just my experiences, Facebook seems poised to be your online passport at the expense of its capabilities as a social communication hub.