Nothing much to add here, but Greg Kuperberg has an excellent article at Slate which clarifies the power and limitations of quantum computers. The article is brief, accessible, and highly accurate. The next time a science journalist contacts you for a story, be sure to pass on a copy of this article as an exemplar of accurate, non-technical descriptions of quantum computing.
For a good laugh, look at the comments on Greg’s article on Slate, and search for “neo78″… I can’t remember the last time I’ve seen someone so, so wrong and yet so, so confident! It’s hilarious. Sad and hilarious. A little knowledge is a dangerous thing.
Those comments make my head hurt.
Some prehistory (?) http://www.scottaaronson.com/blog/?p=1136#comment-53733