The nozzle lift does not require an extra motor. The left nozzle is fixed, and the right nozzle drops below it or lifts above it using a switch on the side of the effector, and there's a piece of plastic on the side that the it runs the switch into to toggle it (judging by the force needed to switch it by hand, it's probably close to the stall torque on the Y axis).
The OLED display does appear to have been replaced with an LCD, for some reason.
The construction is almost identical to the UM2 aside from the effector. It looked like it might have been built out of different materials because of the lack of black dibond edges, but it's the same material with a white core. They did, however, remove the indentations from the top that allow the machines to be stacked.
The Matterhackers guys said that they're still using the same old ultimaker controller boards (still no 32-bit), but have added a single-board computer (Raspberry Pi equivalent) running linux to handle the networking, flash drive, and camera. Camera images are retrieved by Cura using an HTTP request, so it will be easy to set up something else to monitor them.
Nozzle height is calibrated with a capacitive system (most likely measuring the movement of the nozzle/heater block when the printcore spring compresses).
Everything but the print cores was a bit underwhelming, and I would rather have seen those as part of the UM2+ upgrade (probably the only reason this didn't happen was because of the added wires needed to connect to the new components).
Between this and the proliferation of multi-input-single-output bowden systems, I think 2017 will be the year that desktop multi-extrusion really catches on.
On one hand, it's a lot quicker to change a printcore then a nozzle. But it is also more expensive in the initial buy. I've heard some hallway talk about maybe making a core with screw-able nozzles like in the UM2+. But those are just random ideas, nothing has been decided on that area yet.
The nozzles are part of the heater block, which you can unscrew with the proper instructions. However, if you do it improper you will damage or break part of the hotend. So that's not useful if you want to swap often. Note that the UM2 (not the UM2+) has the same issue.