Oops. I redefined my archive naming format yesterday, and apparently LJ decided every one of those renamed posts was new. Sorry for spamming your friends pages.
(For those who might care, I switched from a numbered-permalink scheme to one based off the entry title. This is because it turns out that Movable Type doesn't save entry id numbers in its export-backup utility, so if I ever had to rebuild from scratch, then any links anybody had made to my old articles would be lost. Are any of my old articles really important enough to care about not breaking permalinks? No, not really, but it's still the Right Thing To Do.)