Graphene is in the new developments oval. I am generally optimistic about super-capacitors. But remember that the benchmark is liquid hydrocarbons and for energy density it may not be able to be beaten. You have lots of useable electrons packed along that spine of carbon.
My enthusiasm is also tempered by watching the evolution of the next thing to replace the magnetic disk drive. There was SOS, Magnetic bubbles, optical, magneto-optic and a host of others. Now flash may do the job, or the boffins at IBM will pull another order of magnitude increase in density out of their nether regions. I don't know where the smart money is today, but I do know where it has been.
Technology is hard. 9 out of 10 good ideas don't pan out as successful companies. And remember, these things are not sources of energy, merely really cool gas tanks.
Fight the Free Sh☭t Nation 
"these things are not sources of energy, merely really cool gas tanks."Your point is well made, but I'll dispute the "really cool" part of it. Just look at the energy density of this technology, both in energy per unit mass, and energy per unit volume. All are but a tiny fraction of the gasoline in your "gas tank". Until automobiles are able to safely haul around the energy in 20 gallons of gasoline, and insert it into a vehicle in 5 minutes along side of the road, these technologies are only pipe dreams.