I also backed up everything to my InsaneJournal using LJ-Sec, so I have an online copy of everything. Only 200 posts had to be archived over there, since I had already backed up the bulk of my LJ there.
'Course when I did the LJ-Sec back-up to my InsaneJournal, I accidentally copied everything to LiveJournal instead, which meant I had double posts of everything going back a year. I had to clean everything up so that I wouldn't be double-posting everything to InsaneJournal when I made my second attempt. *headdesk*
Needless to say, it took me hours to fix the mess. And now I'm exhausted.
If you've got time tomorrow (I know, I know...a little late) to backup your LJ before everything goes dead for 4 (or more) hours, read brown_betty's post here for instructions on various backup programs, and my experiences here.
Here's hoping that none of our data bits gets lost.