Cymru am Byth! Some of us may have already known this. :)
Several years ago another DNA study also found unique characteristics among Welsh males. Before a Welshman could be part of the DNA study, he had to prove that he had direct native Welsh ancestry which went back several generations.
That study then pointed to a theory that the unique DNA characteristics traced back to the earliest Welsh might also mean that the Welsh were one of the earliest unique groups and possibly, race of people. Whenever old Wales was invaded, the Welsh hid in the mountains.
Thanks for posting this interesting article, SunkenCiv!