With the release of WordPress 1.5 I couldn’t resist any longer. I made the switch from Movable Type a few days ago. Installation was very simple (<5 minutes), import of all my MT entries was trivial using the import-mt.php script (<5 minutes), setting up the permalinks (1 hours) and redesign of my Kubrick based MT templates was simple since the default theme in WP is also Kubrick (30 minutes). All in all the switch took about two hours and all has been working very good since.
I can strongly recommend doing this switch, if nothing for nothing else to enjoy the powerful but simple admin GUI.