Based off what worked for the successful import of the old photo gallery comments, I've also imported all the threads from the old forum that was abandoned last year when I rebuilt the site.
Normally I wouldn't encourage restarting old threads from a year or more ago, but this is an exception. There was some good stuff going on the forums that just completely died when I switched over to the new forums that I wouldn't mind seeing come back.
Also, since the old forum didn't have threaded replies, the imported threads are flat. I've added options at the bottom of the comments list for switching how the comment threads are displayed, such as turning off threaded views, changing the sort order, etc. Whatever you feel like.
Some of the imported posts are a bit messed up with markup that wasn't translated, and I'll be dealing with those as I come across them - I'm not seeing it as a big deal. I'll also me moving some of the threads around since the categories in the old forum don't match up 1:1 with the new forums.
[ Reposted from my blog on Gothic BC #GothicBC ]