If you are an iPhone user you are still out of luck. The iPhone’s iCalMobile does not support CalDAV like its big brother. This seems like a natural evolution of iCalMobile so I hope Apple is listening. It would give users a free alternative to MobileMe without the push abilities.
You can now sync your Google calendar with iCal. This is great. It greatly simplifies the question of how to sync multiple computers. Now you can think of calendaring like IMAP mail. That is you can use any computer to see your stuff. If you use iCal on your Mac you can use directions from Google to set up your calendar. It works with GMail and GoogleApps accounts. It’s still a little rough and task list items are not supported.