Mailing the story:
Debian Lenny doesn't fix my Nautilus problem, but a look at the bug report tells me why the issue is "resolved"
I half-expected today's massive Debian Lenny update to solve my Nautilus-crashes-when-I-try-to-get-the-properties-of-a-file bug. It did not, but I'm not disappointed. I went back to the original bug report, which was filed with GNOME, not Debian, but is clearly a Debian-only bug. I saw the "solution," but didn't understand it until now. I still don't know how to actually "do" the solution, and for now I'm content to let it ride and see if Debian Testing catches up.