The one they demonstrated could be a new one, but I remember seeing a video of an Evergreen 747 tanker several years ago.
I would be interested to hear how much they will charge for it compared to the DC-10 tanker.
I just read about a recent NASA study of very large tankers and they said they could be effective in open, flat areas, but no so much in mountainous terrain, because they aren't very maneuverable. Unfortunately, most large fires, at least in the West, are in mountainous terrain.
CK