Long drive to the nearest filling station probably will not save a lot in the long run :-( The article did talk about dual fuel systems though.
The dual option is the best of both worlds, use the CNG for day to day but fall back to expensive gas if you find yourself out of range of the next LNG station. I recall a big rig engine manufacture including a similar option for CNG/Disel, I'm hopeing this will get CNG into enough use that it will really become a retail player, a 7 to 10k add on item is way to scarey for retail dispite the payback.