Behind the scenes possible?
There is a video on map creation for the PvP maps, a video on the recording of the orchestral music for Dry Top, a video on how the character face creation choices are designed, etc. etc.
But, to my knowledge, there has not been a video produced showing all the different disciplines used to create a particular release.
(There is a great video on the making of Nightfall found on YouTube, though. Many of the same designers can be found.)