I also think it's because we seem to be getting an influx of new members (with some of the regulars not posting quite as often as they used to), and in the past, one way new Chewers try to get to know people are through posting lists. Whether or not the fact that there's so much list posting going on is one of the reasons the old folks haven't been posting as much, well, that's another discussion. I know that's one of the reasons I've been posting less (also I've realized there's not much point in having a point of view unless you can discuss and defend it at length).
However, I do think that there are those who still try to have decent, thorough conversations about film, Stew, Tommy Five-Tone, Brendan, Helix, among them and of course, Nick, Devin, and the CHUD crew. The Toronto coverage, as people mentioned, was amazing and provoked some good discussion. I know it put a couple of films on my radar that I'd like to try to see.
And, of course, we're in that lull between summer and winter. Once the big pictures, starting with SERENITY and HISTORY OF VIOLENCE going wide this weekend, followed by (at least for me) WALK THE LINE, EVERYTHING IS ILLUMINATED, GOOD NIGHT AND GOOD LUCK, KISS KISS, BANG BANG, ALL THE KING'S MEN, not to mention KONG, I think you're going to see a revitalization of discussion.