D-Wave just demonstrated the first commercial quantum computer. I think it’s too early to say whether the current quantum computing technology is practical, but a promising commercial effort is a good sign.
Quantum computers could represent the sixth generation (electromechanical, relay, vacuum tube, transistor, integrated circuit) of digital computing. They are unlikely to ever replace integrated circuits, but will function as specialized processors for certain (NP-complete) types of problems common in simulating real life and encryption. (Incidentally, quantum computing may one day break all current methods of encryption, but also to introduce theoretically-unbreakable encryption - which has the Feds sniffing.)
Originally uploaded by jurvetson.