I don't know if it's strictly a matter of pack journalism or if there is, perhaps, a grain or two of truth in the notion, but I seem to be seeing a very large number of articles along the theme of "Will Facebook and Twitter kill blogging?" That's certainly the approach taken by CNN Money/Fortune in its "Captain's Blog" section.
I'm not so sure. Sure, some blogs are dying. Some deserve to die. If you're only posting for your friends, then you're going to be better off on Facebook. But if you still have ideas that are worth more than Twitter's 140-characters, then you're going to need the space provided by a blog post. If you want to do more than toss off a couple of one-liners, or just maintain your personal events list, then Facebook is your place. That's pretty much what they're arguing at Baekdal.com.
But even within those limitations, it seems to me that there's plenty of room for blogging. Take a look at what Glenn Reynolds achieves every day with Instapundit. Even without comments, it's still a must-read for me daily, as are a number of other blogs. And the conversation provided on those other blogs through the comments make them far more valuable than the casual comments on Twitter or Facebook.
That's not a putdown of Twitter or Facebook - I spend a lot of time with both, as well as with other social networks. But they haven't replaced blogs - and I believe, in the long run, they won't.