Steven Taylor is about to make the switch and has compiled a handy list of links to various tweaks, plug-ins, and helpful hints.
By all accounts, simply starting a site on WordPress or even importing a relatively bare bones site is a fast and simple do-it-yourself job. If you’re running a Movable Type site with a lot of plug-ins, hacks, and gee whiz features on it (as I was), then I’d recommend spending a few bucks and letting a professional do it for you. Or, if money is tight, do the basic move-over yourself and then pay to have the tweaks done.
There have been a few minor problems that have had to be resolved but, for the most part, the change-over was seamless and virtually invisible to the reader–without loss of any of the functionality that I wanted. The only thing I lost is automatic detection of TrackBacks for outgoing posts, a convenient if unreliable feature in Movable Type.