Big Gav has raised an interesting question on suppression of emergent energy technologies. I can side with the rise of interesting storage ideas such as the ultracapacitor in part because of how much the micro-version of the lowly capacitor has steered high-tech the last few years.
In reality, what we now take for granted, capabilities such as persistent data storage, always-on clocks, and power-down state saving, have lead to a revolution in portable electronics. Things such as solid-state mp3 players have now become the rule, whereas a few years ago, users would have thrown their arms up in disgust trying to keep the things running with any reliability and without extreme care and feeding. You see, the advent of low-power consumption static RAM necessary to run these devices would have proved impossible without the reliable dielectrics that went into the solid state designs for memory. And the little bit of non-leaky capacitors that allowed clock circuitry to keep running has saved "dinking-around" time for lots of users. Lots of people would agree that dynamic RAM has done the trick for all of our desktop computing needs, but fewer acknowledge how static RAM (aka flash and non-volatile) has revolutionized the gizmo arena.
And if we can scale capacitance form the micro to the ultra in the same time-frame as the iPod has existed, we might still get some final juice out of the old reliable capacitor.