Speede, There must be some big advantage to using Nitrogen, I have noticed that several outfits now offer Nitrogen tire inflation outfits that are quite spendy, don't know why someone who wanted to use it could not just use a tank of compressed Nitrogen and a regulator it would be a heck of a lot cheaper?
Nitrogen (using a tank and regulator) is used on suspension struts on large off road haul trucks and the same equipment used to charge these could easily fill tires since it is just a simple regulator, hoses and fittings. Since these struts are partially filled with oil they would certainly diesel under load and shock if regular air was used so it is understandable why they use Nitrogen but I have never seen it used in the tires of these big rigs though, maybe it would be a good idea? The sales pitch for those tire filling rigs (I think even Harbor Freight has one!) claims substantially longer tire life and increased fuel mileage so maybe it is something that will soon become common.