Academic Discussions

An article in today's online Chronicle of Higher Education asks whether academic e-mail lists, notably those hosted by H-Net, are moribund. Some scholars claim that blogs, Facebook, and Twitter are taking their place.
As a scholar who's used all of these except Twitter (and I'm not a stranger to Twitter, I just don't use it), my reaction was that this was ridiculous. Why?
Blogs, due to the flexibility of the form, have an important place (or should) in the scholarly world. Individuals and groups blog on a wide variety of topics. On the other hand, I think few people really want to keep track of more than about ten active blogs. Sure, you can read your blogs via a feed, but the more blogs you track, the less likely you are to notice that any individual blog has a new post. The feed doesn't show the discussion that a post has prompted, either.
Facebook is good for keeping track of friends, and some academic exchange does take place, but the scholarly is easily lost amid the more social material. More significantly, to post something of any length on Facebook, you have to put it in a Note, and comments of any significant length have to go in other Notes because the comment field only allows a certain number of characters (I'm not sure how many, but it's not a lot). Besides, while you can group your contacts within Facebook, there isn't really any good way of separating academe from everything else. I know there are some ways around this--one person I know has a Facebook identity for use with friends and a separate one for use with students, but since many of his friends are also colleagues, I think many of the links get posted in both places.
Twitter seems particularly unsuited to take over. With a 140-character limit to each Twitter message, that's a medium with severe limitations. You can broadcast your headline news with it, but how much humanities discussion is something you want to read in capsule form?
Thus, blogs, Facebook, and Twitter all have their uses, but their uses are rather different from the uses of listservs. I think I subscribe to about six academic lists, plus a shifting number of lists relating to software and other topics, which can get me up to something like twenty simultaneous lists at times. Obviously I don't read all of these messages, and I certainly don't read them all right when they arrive. But there they are, I've got them, and the ones I don't delete are categorizable and searchable. In one of those moments of semi-brain-deadness, I can go through a batch of art history or Slavic emails and see what's happening.
This, however, gets to one of the other points made in the Chronicle piece. While listservs are great for disseminating conference announcements, job postings, and book reviews, their use as a means of actual discussion has dwindled.
The amount of discussion depends on the list, though, and this has a lot to do with the number of subscribers. Too few subscribers, and the list has nothing to say; too many, and it gets noisy until people either unsubscribe or turn it into an announcement-only list. H-ArtHist has no discussion that I can see, just announcements, most of which are of no particular interest to me. This is not surprising, considering the list tries to cover the entire field, internationally. The likelihood of my hopping on a plane at the last minute to attend tomorrow's German symposium on (I'm making this up) dog iconography in 15th century Japan is pretty small. But other lists do have discussion, particularly about books people have read or want to read. H-HistSex has pretty good discussion (as it ought to!) and often H-Women does as well. Not endless discussion, but readable.
I'm not sure how the question of scholarly discussion should be resolved. The historians have the benefit of all the littler special-interest lists, which can sustain some specific discussions, but as far as I can tell, the art historians are pretty much stuck with one non-discussion list. HGCEA sends out email to its members, but I wouldn't call that a discussion list. Likewise AAH. But perhaps I'm missing something.
Where are all those art-history discussions, anyway?