Not much to add beyond what's already been said. The linked article isn't very good, but the paper itself may be correct. I haven’t checked the paper, but the possibility of this kind of break is quite plausible. The reason is that when quantum cryptography researchers say quantum cryptography is "unbreakable", there’s many unspoken caveats. All they mean is that the theoretical scheme itself is unbreakable. Of course, (a) the real-world implementation may differ in subtle ways from the theoretical scheme; and (b) side-channel attacks cannot be ruled out. Both these possibilities can potentially be exploited to crack quantum cryptography. I’ve written about this at some length at: http://michaelnielsen.org/blog/?p=122

If you feel a bit cheated by this state of affairs, given the hype that often surrounds quantum cryptography, I don’t blame you.