OK, so I've been scrounging around Blogger's Support pages, checking scripts on my template, and sending e-mail to Support for nothing... the one time I don't read the Status Report first is the one time when it actually applies to me!
Curiously, only the archive links to posts from July, August, and September are down, but everything before July '03 works... I have no idea why only the last three months have gone AWOL, but at least I know the individual posts are still actually there, it's just the Blogger pages of the posts formatted on the template are missing.
Once Blogger gets the archive pages up again, I'm going to archive the entire blog... I would be absolutely choked if 14 months of my life just disappeared into the ether like that.