[Dovecot] Converting from 1.12 to 2.0 questions about mail location?

I'm building a new server and using a newer version of ubuntu server that uses Dovecot 2.0. I thought I would like to use Maildir instead of the mbox that was used in the previous server. What do I have to do to convert my mbox mail to Maildir? Or should I just use mbox and copy it over :-)?

Thanks,

--

Knute Johnson