Cars and buses will run on empty

This one is a pretty safe bet too. The switch from fossil fuel powered vehicles is already underway and, although there are a few potential energy sources including hydrogen and various biofuels vying for consideration, IBM predicts that improved battery technology will be the technology to power the next generation of eco-friendly vehicles. It says the new batteries won’t need to be recharged for days or months at a time, depending on how often the vehicles are driven, and will allow trips of 300 to 500 miles (480 – 800km) on a single charge. Also smart grids in cities will allow vehicles to be charged in public places using renewable energy, such as wind power, for charging so they no longer rely on coal-powered plants.

taco bell has made similar predictions. they are developing a car that runs off methane, with fuel ports located in each seat. they're gambling on customers eating more of their product to power their vehicles.