Adam Greenfield claims that blogging is a dying art; that things are moving towards the sort of little blurbs that you see on twittr and Tumblr and, to a lesser extent, those little Facebook status thingies.
He notes that Flickr ain't what it once was, either.
Me, what I've noticed is that blogging is maturing, but more importantly the idea of being able to do so has matured. The big revelation back in 2001/2002 was that you could, quite easily, put your thoughts up on the Internet for all to see, and (presumably) comment upon. Yes, people have been able to write things on the Internet since they first logged on, but blogs were unique in their ease of use and their reflection of the writer's personality. Websites (often? usually?) belonged to someone else, but a blog belonged to you, in a way far more egalitarian than you saw previously. This sparked an explosion of self-expression which mutated into flickr and Youtube and all the other things we see today.
Thing is, we're used to it. It's not new anymore. If you want to have your own "column", you can. It's presumed. And since it's not new, society as a whole is starting to suffer from Ted Barlow's disease, where the initial explosion of expression gives way to a kind of ambivalence about the whole thing. You've posted, talked, videoed, and everything else, but the magic is gone. You've let it all hang out, but what's the next step?
Plus, as the pseudonymity that was ubiquitous in the 'net's older days started to decline, and people started assuming that you had to express using your real name, people started realizing exactly what they were doing: publishing. It's quite likely that what you write isn't going to go anywhere, and many of those who had the potential to make interesting and unique insights--in a unique voice--are moving away from it, because they're concerned about what it would mean for their social life and career.
Those that are left are those who can already write their thoughts with impunity: academics, opinion journalists, some authors, and others along that line. Yes, what they have to say is interesting, but by and large we've already read it. I don't want to read what Whatzisname has to say so much as I want to read what the other guy without the column has to say, but he's not going to say a damned thing to anybody but the same-old same-old journalists that we already know and are entirely sick of. The "let it all hang out" ethos isn't surviving the cold light of day, but things like Facebook are too entrenched in popular culture for the Internet to easily move back to the culture of (ideally) respectful pseudonymity that it once embraced.
(Or, of course, they'll end up in walled gardens, like mailing lists or exclusive webforums.)
In any case, it does raise the question of what will replace the current Facebook-dominated paradigm. I'd say, but if I knew, I'd be too busy trying to make money off it.