yes it synchs ical and gcalendar bidirectionally!!!
There are some issues though. If you delete an event in ical, then it tries to import it again from google instead of also deleting it in google. And if you edit some properties in gcalendar it doesn't reflect them in ical.
Well, anyway it is a great piece of software. Installing it was fairly easy. Many thanks to the author for creating this code and making if freely available!