John, the Entourage team meets regularly with the Exchange team to help us determine what direction we need to go in the future. For Entourage 12, we'll continue to use DAV for our synchronization mailbox.
I've seen and coded against the Exchange 12 web services. They are going to make developing Exchange solutions, such as Entourage, a whole heck of a lot easier. Our ability to adopt these changes will have to balanced against the Entourage team's resources and the number of Exchange 2000, 2003, and 12 users we have to solve problems for. As you well know, we still don't have everything that many people think is important, regardless of Exchange server version (e.g. OOF).
I don't think you should read so much doom and gloom into things. The Entourage team has worked hard to demonstrate we want to make things better with the recently released SP2. Many of the optimizations you see that resulted in improved synchs were the result of us working closely with the Exchange team. What makes you think that this is going to change?