Its interesting that in Oct the price of electricity in Tx dropped to 0 (for brief time). They were basically giving it away because there isn't a way to store it. http://cleantechnica.com/2011/10/20/wholesale-price-of-elect...
Aquion is definitely an exciting competitor, and we wish them all the best. It is an honor to have such a worthy competitor. I think we'll bring out the best in each other.
They probably can reach the smallest scales better than we can, though I think we're going to give them a run for their money at mid - larger scales. It will be a challenge to come up with a system nearly so low cost and long lasting as one using compressed air. There are also some very interesting things we can do with low-grade heat, but that is another story. :-)
Granted, even a little negative doesn't mean you'll make money by turning on all the lights and cranking the A/C. Distribution charges and etc usually add a few cents per kWh.