Re Comment 10 by rjohn19, I will give that question a try. These computers will not be used for a straight forward computation like adding 1 + 1. They will be used in searching for solutions in complex multivalued problems like cracking codes, or predicting protein folding. It has to be structured such that all the components of the computation are held in superposition at the same time, and finding the answer is what collapses that into said answer. Yes, that is still quite a bit ahead in the development. You can think if it as if a student that you give a problem to could instantly clone him or her self into a whole room of students each approaching the problem from a different starting guess at the answer, and the first one who gets a check back correct on that guess holds up a hand and they all collapse back to be that one student. Very strange, I know, but that is what we get access to at the quantum level.

Hope that helps.