Following up on this post that I wrote back in July, the MobileMe calendaring system has come out of Beta. Which means that if you are using the MobileMe service and you are on Snow Leopard (or Leopard) your iCal calendar should automatically switch over to WebDAV. As well as your iPhone's calendar if you are running 4.0.
The nicest part about the system is the ability to invite other people to events from your iPhone and iCal, as well as see their Free/Busy schedules.
Update: Apple's article on the subject.