Anything you want to know about this new engine can be found on the diesel forum for Fords........
www.thedielsestop.com these guys are way past the rumor stage. It should show up after a short model run on the '10s I believe--kinda like the 7.3 to 6.0, then the 6.0 to 6.4. I believe it is going to have an urea injection system to control emissions, making it way more complicated than the 6.4 or 6.0. It also is a Ford enging, not a Navistar.
So far, Ford has marketed the 6.0 as being more fuel efficient than the 7.3--NOT--and the 6.4 as better than the 6.0 on fuel--NOT. So don't expect any better fuel mileage again til it is out and reports come back.
Joe