Vikings and our Ancestors DNA

I don't know a lot about DNA, just the basic facts. I read an article that made me wonder how mixed-up we may be.

The October 2010 issue of "Smithsonian" magazine has an article about "A Viking Mystery". Although the entire article is very interesting, there were  two statements on page 66 that make me wonder. " The Vikings were a Scandinavian people from Denmark, Norway, and Sweden. And Dublin, one of  the largest Viking cities in the British Isles, became a major European slave-trading center, where, probably, ten of thousands of kidnapped Irishmen, Scotsmen, Anglo-Saxons and others were bought and sold." This probably started around A.D. 1000.

This sounds like a lot of mixed-up people. If someone would like to leave a comment -in simple language please-do all six of these countries have a basic DNA with small parts of each separate country? We know about Scots-Irish, but I've never heard of Scots-Norwegians. Or Viking -Anglo Saxons. Must be some.

Just wondering.