I do recall reading this a little while back. In regards to the "twin turbo" version, not sure how legitimate those "sources" are that they claim to have. If you need to tow enough with a Super Duty that you need that kind of power and torque, the Powerstroke is the only option. I'm suspecting the 6.8 will be the lower displacement version of the "Godzilla" for commercial/fleets who want the increased low end torque, higher horsepower, and better fuel economy of the "Godzilla" engine over the standard 6.2.
It's on the internet so it's 100% factual.
The 6.8 is being made at the Windsor, ON plant; It was announced awhile ago at by a union representative I believe. This all may fall apart due to emission standards now.