It was a small part of the Worldcon but I enjoyed it, the guy was quite chatty and interested in people who had met or known Terry, I was asked if I wanted to be filmed but said I did not think I would be any good in front of the camera.
The US one was an independent production by some fans in the North American Discworld Connection (not associated with NADWCON2017) - they ran a Kickstarter campaign to raise funds to make the doco at WorldCon last year. I'm hoping it's going to be ready by mid next year.
I think there's another BBC-produced documentary coming next year too, but that's completely separate.
Rob did say something about a Biography coming out at some point in the future, but that was back at the memorial... There isn't anything more about it anywhere that I could find.