So people have been wondering WHAT THE HECK I've been up to the last year, since I've been qute... silent....
The short story is... this:
The main work that was done was to turn mental ray into an ActiveShade renderer, i.e. that you can work with interactively. Also, for the already ActiveShade-capable renderer iRay, we improved the responsivness of a lot of the updates (no longer waits for mouse-up to apply changes).
Be aware that not every scene edit is supported in ActiveShade, but a lot more than what was supported before now works much more streamlined. In 2014, running iRay ActiveShade was a bit of a pain. Now, in 2015, running both mr and iRay ActiveShade should be a much more pleasant experience where you can actually get real lighting- and shading work done.
About the other features mentioned in the video - I will post more about those as time permits, but the short story is that we enabled iRay string options, and made iRay LPE's (Light Path Expressions) into render elements, which can be quite powerful!
More details later....
UPDATE: There is one minor ERROR in the above video, though. As a matter of fact iRay does not have a "Shadow" pass. iRay LPE's are about light, and shadows are the absence of light. Only oldschool "non-physical" renderers saw shadows as a "thing" that you can output separately. What you do in iRay is instead to separate different types of lights. You can get a similar amount of control (in a more physically correct way) by balancing lights. But there is no "shadow" element. As a matter of fact, anyone who took my mry201 mental ray FXPhd course know, that "Shadow" passes are evil, bad, and never actually work anyway (with the exception of shadow passes for the background for compositing, of course)