The new powerful ,safe long lasting lithium battereis are the key to the future. They are non toxic and very light weight. You could not pick a better material than lithium. 
As the moores law of technology comes into play and prices drop it will be all batteries making technology better. 
 
Some of the new makers like A123 Altair nano and valence are just starting to release these as large format battereis suitable for vehicles. It will be an exciting next few years.