I don't see anything revolutionary. They aim was to find the definite genetic signature of the so called farmers and they failed not testing the most important thing: Y-DNA.
It doesn't surprise me at all to see MtDNA K, but don't forget that according to another research in Greece this haplogroup was already present there by the Mesolithic. So I'm so sorry, but they proved nothing.
Hope they test Y-DNA someday...so we can discuss the issue supported by better clues.