It messed up the categories, and in sorting it out, broke links to many, many posts, mostly in the "Food & Fitness" Category.
Many other problems as well. We'll see how it turn out. Not a happy camper, right now.
Later: Well, having now worked with WordPress over at the company blog, I think I've decided to make the switch on HonestyLog. I'll for sure use the same guys to design. TypePad has been pretty flawless, and most of the upgrades and improvements that happen without you having to upgrade your own server installation have been welcome. Other obvious should-bees have been way too long in the making (like, for instance, getting your links to open in a new tab or window without using a global widget that kills Firefox's ability to remember commenter personal info).
Anyone know of a good paid hosting service for hosting WordPress?