Fast forward to 3:28 if you want to get to the part when the electronics start going in.
The computers for all the video switch, editing, transcoding, etc and most of the other hardware is in the basement. Cabling goes up through holes in the wood floor for easy access.
And yes, the director's console ("Control Desk") DOES rotate to face whichever studio is live at the moment.
https://www.youtube.com/watch?v=8HZIQGZcNm4
Wiki here with a detailed list of equipment they use with photos: http://wiki.twit.tv/wiki/TWiT_Brick_House_Equipment
