I'll bet it'll be popular with folks who haul for a living, especially with the manual 6spd and Gear Vendors overdrive and "sleeper" cab in the rear.
I was talking to a couple of guys who had delivered two RV's to our dealership last week. They said with the old 12 valve Cummins with an overdrive unit, they were able to get almost 30 mpg towing RV's. While I took that with a "I'll believe it when I see it" attitude, they did also say that with the double overdrive, 2000 rpm will get you going about 90 mph.