I've posted a scan of the Full Brochure of the Dynamixel line here http://robosavvy.com/forum/viewtopic.php?p=35721#35721
It seems there will be 3 types of actuators with varying torques up to ~400kgf.cm (39 Nm)!
Additionally the new line seems to support a new interface (CAN in addition to RS485) and, according to the brochure, introduces Torque based control.
This is a feature that we see requested from time to time and it seems these actuators will have it.
Regarding the Cycloid reduction gear there's not much on the brochures but there are some pictures that might help shed some more light on how it works.