The good FIM guys in Seattle just released a very much needed list of deprecated features for the FIM 2010 Synchronization Service.
This is a MUST read/study list. All deprecated features of the FIM Synchronization Service that are still available in FIM 2010 R2 are discussed and make no mistake - these features are scheduled to be removed in a future release of FIM. You should not use deprecated features in new applications.
So no doubt, there are definitely some actions for you too take on your current FIM 2010 installation or if you're planning to deploy newer versions of FIM in the near future. Make sure that your roadmap for your installation aligns with the facts in this document from Microsoft.
I'll keep a close watch on this list and I really hope that Microsoft keeps it in a current state moving forward as these decisions affects a lot of installations around the world.
Oh, and you can find the list here.