Part of the reason car makers are producing
flex-fuel type vehicles are that they get CAFE (Corporate Average Fuel Economy) credits for those vehicles.
My understanding is that the fleet average fuel economy has to meet a certain minimum (I can't remember the number right now). If they sell a flex-fuel vehicle, they get to use a higher mileage number for that vehicle, even though it will probably get less mileage using something like E-85 fuel.
The credits they get for selling flex-fuel vehicles increases their CAFE calculations and prevent them from having to pay fines. That leaves them free to sell more low mileage/higher profit vehicles, like pick up trucks and large SUV's.
Maybe that is why they are starting to switch. GM has been doing this for a while and all the car magazines seem to think the only reason is the CAFE numbers. Most people that buy the flex-fuel vehicles continue to use gas because E-85 is just not available.