I'm in the process of importing a pretty big Movable Type blog to WordPress. It went OK for a while, but at this point, it's running for over 10 minutes, and depending on comments on a post, it may only import part of one post.
There are currently 17,170 posts and 240,208 comments. The comments seem to be the slowest; there are posts with hundreds of comments, and it only makes it through around 100 before bombing. Luckily, my customer doesn't care too much about the dropped end of those threads, but it's turned the import into a multi-week affair.
Any ideas of things to try to speed this up?