Are there others that you can buy? As far as I know, D-Wave is the only one out of the lab. I'm totally a D-Wave skeptic, but I do have to state that the scientists who tested this thing sound like idiots, unless they really did try quantum annealing. If the D-Wave guys say they tried the wrong set of equations for the device, I'm inclined to believe them.

Even though I don't even believe this thing is really a quantum computer, there are much more specific and defined ways to poke holes in D-Wave than just by running some tests and comparing speed. D-Wave has, very specifically, targeted this machine at one function: http://en.wikipedia.org/wiki/Quantum_annealing

Unless you're doing quantum annealing on the D-Wave, it might as well be a toaster, an Android phone, or a Windows PC. It's made to do only quantum annealing.

Did D-Wave 2 somehow expand its capabilities? I'm basing this on D-Wave 1 knowledge, but I cannot imagine anything really changed except the number of Qbits inside the thing.

All this having been said, the D-Wave has yet to prove that it is even doing Quantum Annealing, let alone that it's faster than a traditional computer at this problem set. No one has shown it to be faster than traditional outside of D-Wave.