I think the only part of "general-purpose quantum computer" D-Wave can claim is the "computer" part. They have not proven that any part of their annealing is "quantum". They have pretty epic lithography/fabrication skills, and are barreling ahead without any regard for coherence. They also have just an insane number of control lines, so there's some innovation there.

But their net worth becomes negative if you count the bad press for quantum computing in having a charlatan claim they have 1024 qubits and are "500,000" times faster at solving Sudoku. Other fields are having this PR problem too, where even careful program reviews are getting brutalized by the PR news cycle (see recent dark-matter experiment: http://profmattstrassler.com/2013/04/03/ams-presents-some-fi... -- forgive the typography)

Is it possible that in the future rather than having a sort of general "quantum computer", something like quantum processors will be built for specific computing tasks? Each very different in config and unique, specifically designed and used for one thing and one thing only?

This is useful becaue it would mean that we could see exactly how reactions take place and perhaps even engineer interesting chemical/biological phenomena. Certain processes in your body depend on proteins moving certain substances or reacting in certain ways, and if we can simulate all that with a computer, we can start to build chemical/biological tools for, for example, fighting certain diseases

Well - it's more that there are entire classes of things that we can't simulate in any reasonable amount of time that (in theory) QCs should be very good at.

Protein folding for example. Finding the lowest energy state that protein's fold into is really, really hard and slow. QCs can theoretically do it very, very quickly. This opens up whole areas of experimentation and validation that are closed to us at the moment because the feedback cycle on solutions is so darn slow and/or inaccurate.

Protein folding errors are at the heart of diseases like Alzheimer’s, Huntington’s and Parkinsons. QCs capable of simulating the chemistry involved would be a huge help in attacking those problems.

  http://www.gromacs.org/About_Gromacs

The aim of my question was to see if chemically accurate simulations come up with significantly different answers or to see if the current way of doing things is a good enough approximation.

Currently such investigations are limited in scope by the large computational resources required to perform a single quantum mechanical calculation on a molecular fragment. With quantum computers, tens of thousands of such calculations could be performed and the results could be used to optimize new molecular force fields through multivariate regression.