from the wiki page:
D-Wave has been heavily criticized by some scientists in the quantum computing field. According to Scott Aaronson, a Computer Science professor at MIT who specializes in the theory of quantum computing, D-Wave's demonstration did not prove anything about the workings of the computer. He claimed a useful quantum computer would require a huge breakthrough in physics, which has not been published or shared with the physics community. Dr. Aaronson has maintained or updated his criticisms on his blog. See  for a reaction to Scott Aaronson's criticisms by Dr. David Bacon, a professor at the University of Washington.
Umesh Vazirani, a professor at UC Berkeley and one of the founders of quantum complexity theory, made the following criticism:
"Their claimed speedup over classical algorithms appears to be based on a misunderstanding of a paper my colleagues van Dam, Mosca and I wrote on "The power of adiabatic quantum computing." That speed up unfortunately does not hold in the setting at hand, and therefore D-Wave's "quantum computer" even if it turns out to be a true quantum computer, and even if it can be scaled to thousands of qubits, would likely not be more powerful than a cell phone."
Wim van Dam, a professor at UC Santa Barbara, summarized the current scientific community consensus in the journal Nature:
"At the moment it is impossible to say if D-Wave's quantum computer is intrinsically equivalent to a classical computer or not. So until more is known about their error rates, caveat emptor is the least one can say."
I'll assume we're no where near to actually worry about it.