One thing I noticed in The Social Network (fantastic movie, by the way) is when Zuckerberg was using LiveJournal, he posted very quick, single paragraph updates, basically bereft of any external links. It's not the way most of my LJ friends post, certainly -- with the exception of those who dump twitter to their livejournal, most of my friends list post multiple paragraphs, or at the very least are writing a paragraph linking to a multi-paragraph content, but of course, this is a very biased selection. It certainly fits in with facebook status updates or even twitter comments, though.
Incidentally, because I had my doubts regarding the accuracy of parts of the film: the blog entries in the film match closely, if not exactly, the excerpts of his actual blog shown in this Slate story, and this Quora thread has a lot of other commentary.
- The Social Network