I don't see why they would continue to increase displacement given that the engine ought to have a higher specific output (hp/l). The new engine will be a more sophisticated CGI block with an overhead cam(s) setup. Read about the "lion" series of turbodiesels they have in europe....
Ford AJD-V6/PSA DT17 - Wikipedia, the free encyclopedia
The 3.6 L V8 is built at Dagenham Engine Plant by Ford of Europe. It is a twin-turbocharged Diesel V8 producing 270 PS (266 hp/199 kW) and 640 N·m (472 ft·lbf).
The powerstroke will have a far different duty cycle than that engine though, so I wouldn't expect such a huge amount of horsepower per liter of displacement. By the way, that's where someone came up with 500.
270 hp (seen above) / 3.6l = 75hp/l
500/75 = 6.7
500 hp seems excessive since that kind of power output has all kinds of cooling and drivetrain wear implications. I think the power output will be like those of the past generation engines, a 50hp or so bump over the previous one. That said, if their spies indicate Dodge and Chevy have something powerful up their sleeves, who knows what we'll get.
And yeah, ford is fed up with International producing engines that have issues in the beginning and also over pricing/warranty issues. While I haven't read much on diesel emissions strategies, I know enough from cars to say that the more control you have over valve timing events, the better.
Ford is ditching Navistar. The 6.4s are having its fair share of problem, nothing surprising from navistar. Also the 6.4 was always "unofficially" a temporary engine.
With the 6.4 having not the greatest reliability and it's milage unpredictable/poor its a good idea. They might of still been under contract with International too which might be the reason they developed the 6.4, International wanted anther chance to try and keep Ford as a customer.
I have high hopes. They're probably dishing out lots for diesel research considering the 4.4 is coming at the same time and the 4.4 could very well steal the 1/2 market from gassers effectively killing non domestic trucks provided the price tag isn't to steep and diesel prices don't skyrocket. Its been in the process for too long already to cancel due to inflated prices. Inflation is nothing new.
Yeah, I was just thinking the same thing about the 4.4. High initial cost + sagging pickup truck sales + brutally high diesel prices = bad news. Whatever sales they get I predict will be cannibalized from the F250 market