Actually its not "mixed" with beer. Malted barley & hops are added during the "brewing" to make
Braggot.
Mead mixed with other fruits or spices go by different names as well:
Mead with grapes: Pyment
Mead with spices: Metheglin
Mead with berries: Melomel
Mead with apples (cider): Cyser
All are quite tasty.
Mead is quite a complex beverage. Honey is 100% fermentable, meaning all the sugar in it will be eaten by the yeast during fermentation. This leaves the aroma & flavor characteristics of the flowers (or plants, weeds, trees, etc) from where the bees got their nectar.
You can make mead quite simply. Dilute honey with water (typically 3-4lbs honey per gallon), heat to 160deg (F) to pasteurize, cool to room temp, add yeast & nutrients, and wait. At least 6mos to a year. Mead ages very well.
Here's a good site:
http://www.gotmead.com/You can also buy decent mead kits here:
http://www.northernbrewer.com/mead.htmlWas the Danish stuff you tried
Viking Blod by chance?

This is actually mead made with a little hops & hibiscus. It was real good, and at 19%, knocks you down quick.

I find mead quite tasty. I say if you have an opportunity to try some, go for it.