The countryside was strip farmed well into the middle ages
Much of our legal system we owe to Henry II
William I abolished slavery which was still practiced in Saxon England (fair play?!!?)
Then wer have the issue of weregild where a man's life had a fixed value and if you killed him you payed it and that was the punishment.
I really think people have an attachment to a rather idealised saxon England - our cultural values of fair play have more to do with the Enlightenment and people like Voltaire and Rousseau than with Saxon warlords like Harold
I think people are rather attached to a rather romanticised idea of Saxon England - yes I do think Tolkein has rather something to do with that!
As for DNA I did enjoy the 100% English program on Channel 4 when they looked at the DNA of a rumber of leading right wingers.
http://en.wikipedia.org/wiki/100%25_English
One woman from some sort of battle of hastings society tried to sue them after she was told that she had significant sub-sarahan african genes in her "very recent familly tree".
Disappointingly though Norman Tebbit did turn out to have the highest level of native genetic markers