MovablePress is a php script that takes information directly from a WordPress database and converts it to a form suitable for import into Movable Type.
The script is at /stuff/movablepress.php
All you have to do is download that file, edit it to provide your database information, upload it to your web server, and navigate to it in a web browser.
Then copy all the output text into a new file, and that’s the file you can import into Movable Type.
Right now trackbacks and pingbacks aren’t implemented, mostly because I don’t use them on my site.