I've just made a quick point release of IMAPClient. Mark Hammond is interested in using it for a project he's working on but the licenses (GPL and MPL) were incompatible. I was thinking about relaxing the license of IMAPClient anyway so this presented a good opportunity to make the switch.
Work on the 0.6 release is coming along. This version will fix a number issues with parsing of FETCH responses - the FETCH parsing code is being completely rewritten. This is the first time that IMAPClient will bypass most of imaplib for some functionality. It's looking like that at some point IMAPClient may not use imaplib at all.
IMAPClient can be installed from PyPI using pip install IMAPClient or easy_install IMAPClient. It can also be downloaded from the IMAPClient project page. As always, feedback and patches are most welcome.