"a D-Wave computation is both quantum and analog, with nothing resembling a discrete instruction or basic operation that can be counted"
So it's not really a quantum computer at all in the sense that the term is usually understood nowadays. It's an analog computer. And if you believe Scott Aaronson (and I do) it's a classical analog computer.
http://www.dwavesys.com/sites/default/files/ttt_arxiv_v1.pdf
The money quote:
"a D-Wave computation is both quantum and analog, with nothing resembling a discrete instruction or basic operation that can be counted"
So it's not really a quantum computer at all in the sense that the term is usually understood nowadays. It's an analog computer. And if you believe Scott Aaronson (and I do) it's a classical analog computer.