Hey, the deal with quantum computers is that they might be able to operate at extreme speeds, like for weather simulation or protein folding, or brain modeling.
Depending on your take on quantum physics, maybe it would be done by computing simultaneously in an large number of parallel universes. (Did I nerd out? Well, this explains part of my passion for LOST, and also FlashForward.)
A demo of a quantum calculation carried out by Japanese researchers has yielded some pretty mind-blowing results: a single molecule can perform a complex calculation thousands of times faster than a conventional computer.
A proof-of-principle test run of a discrete Fourier transform -- a common calculation using spectral analysis and data compression, among other things -- performed with a single iodine molecule transpired very well, putting all the molecules in your PC to shame.
If you're worried about computers developing self-awareness, and maybe deciding we're redundant, this might matter.