I just imported my entire Radio Userland weblog into Movable Type at http://www.mc-development.com/~mike, using a modified version of Aaron’s script.
I learned a lot more Python than I ever intended to in the process to get it running under Mac OS X. The date functions as written wouldn’t work, so I ended up changing it to:
date = time.strftime("%m/%d/%Y %H:%M:%S",rfc822.parsedate(getDate.search(entry).groups()[0]))