In particular, the addition of the Lists feature had slipped past me somehow: this is fairly similar to LJ's custom friend lists for purposes of reading. (Although not yet for permissions: I believe Twitter is still all-or-nothing -- either all your posts are locked, or all are public.) List means that you no longer have to wade through everybody you've ever friended in order to read your flist; I consider it a core feature for any social network. It's new and a bit immature -- client support is still generally weak -- but it's getting there.
Anyway, between that and the argument that it can be a good concise information source *if* you choose your friendlist carefully, I've decided to start using it again. How much, and exactly for what, will remain to be seen, but my general operating theory is that Twitter is mainly good at dissemination of news, so that's where I'll be focusing. Expect me to be tweeting and retweeting news that I consider interesting, as well as links that are interesting in and of themselves and don't need a lot of comment. (When I *do* feel the need to say something more in-depth, it'll probably stay here on LJ.) Knowing me, I suspect there will be a fair number of links about technology, politics and economics, and maybe occasional ones about the SCA.
Feel free to friend me over there -- I'm jducoeur as usual. I will tend to re-follow people who I know personally, but make no promises. I don't promise to read every tweet everybody sends: I'm going to be mostly reading custom Lists, and in general, I'm more likely to really pay attention to people who I am closer to, and/or who have interesting things to say. (Which is pretty much the way I mostly read LJ.)
I'm also using Facebook a bit more, but honestly I find the Facebook feed even less useful than Twitter's -- the social equation makes it even more prone to useless blather, so the signal to noise ratio is even worse. So I'm tentatively using FB more for purely social stuff, and Twitter more for news and information.
BTW, I will *not* be using one of those tools that reposts Tweets to LJ. Seriously, if someone wants to read my tweets, they can do it on the tool for the purpose. I'm finding it really kind of annoying to reread the same messages on Twitter, Facebook and LJ because of the reposting tools. (It's actually making me think about whether to continue linking my blog into FB.) I might change my mind if sites start coming up with decent ways to filter these reposts out, but for now I'm finding them more trouble than they are worth...