If you are a registered user, the beta doesn't have any expiration date.
A new beta version will be released in the next days with a correction for some potential unresolved items, and new features. If everything works well with this version, an official version will be released.
Thanks mate. I have to say I'm suprised that this forum isnt a lot busier given the amount of people that have been requesting a way to sync Thunderbird with PPC. Do you advertise it on the PPC sites like http://www.pocketgear.com etc? I think a lot more people would be interested in birdiesync if they knew it existed..