Personally, I think the HTTYD coaster is going to be from Gestlauer. I mean, they're clearly willing to work with them (like the Sky-Fly's in the same land), and there won't be any reliability problems like there would be with Intamin.
On one hand though, if it's going to be a simpler system for Intamin that doesn't have any "gimmicks", then it might be a better option to continue with Intamin.
That said..Gestlauer is a nice thought.