In the near future we will see more diesels on the road. My Jetta TDI easily gets 45mpg and if I work it I get 50-54. My F250 pulling a 23 foot trailer just got 14mpg at highway speeds. I will be getting a hitch for the TDI soon, wife doesn't like doing more than 200 miles a day and the GS just doesn't haul everything she "needs", so I will pull the GS to some destination, setup the tent, and ride to see the sights, including non paved areas not easily accessible in the car
On another note? The USMC is getting rid of their diesel KLRs. First dibs are going to military motorcycle training programs but we will soon see them up for sale. I will have one, to go with the truck, car, and backhoe
The torque and range with the IMS tank on those things is incredible.