Unfortunately, that doesn't seem to be the case. But I still have my fingers crossed.
Chain of thoughts, with mail still on my mind: I only have 164mb of mail, but I delete old messages because otherwise my mailboxes are too slow. Apparently, even djb doesn't recommend using maildir in a MUA. jwz's mail summarization rant came up on the Pan list (because they've been using a database backend). I think the only MUAs that do summarization are pine and evolution (and I suppose old Mozillas) and I don't much want to use those.