It'll probably be pricey, but I would bet that a lot of departments will buy it because it is 'zero' profile, and it's integrated into the vehicle (which just makes it easy to order). Ford will also need to offer different models for red/blue and all-blue agencies, and will likely need to offer all-red as well.
It's interesting to see car manufacturers get more and more into vehicle outfitting. They're banking on the fact that fleet managers like things that are easy (let's face it , making decisions on a full vehicle upfit is pretty complex) and they're willing to pay for the convenience factor.
Ford used to be really big on crash-testing everything and ensuring it all meets SAE standards, etc. I wonder if, because it's behind glass, this light will meet SAE Class 1 standards. If not, Ford could open themselves up to a lot of liability. I see that they're saying that if you order this option, they give you a windshield without the sun-strip (tinting) at the top so that the light doesn't have to go through the tint.
The tint is actually nice because it hides the bar, and generally isn't a big deal if you're using a bright interior bar.
However, all you distributors and outfitters (like we are) should be nervous about this trend that's taking business away from us.