We are currently looking to move from Collaborate: Original Experience to Collaborate: Ultra at the end of 2016. It is at that time that, assuming Blackboard meets their release goals, the feature parity between the two versions will be such that we can make the change.
Right now, our current plan is to cut over from Original to Ultra at the end of the year without any overlap. Sometime in the next few months we will do a demo of the Ultra interface and begin showing faculty how it works, providing training, documentation, etc. The main reason for not actively deploying both is that I am concerned that students who use Ultra and have a good experience will then, if forced to use Original in another course, have an even worse experience. What are others doing in this regard? Have you already transitioned? Have you deployed both? How is that going?