I've been experimenting with plugins with a view of moving a copy of Movable Type over to WordPress. I didn't want to lose all the data in MT so the normal import process wasn't ideal. Thankfully this plugin did the trick.
My only comment is that it doesn't import the "Excerpt" field from Movable Type which meant I had to edit the plugin myself. This wasn't hard but it would be a useful addition for a future version for those that are less tech savvy.