What can I say, John Ringo's got me hooked on his Legacy of the Aldenata series- and all of the badassery that it entails:
If ever there was a song screaming to be turned into a heavy metal cover by a band like, say, ENSIFERUM or ELUVEITIE, this would be it.
To get an idea of what that would sound like, check out ENSIFERUM's "Victory Song":
See also ELUVEITIE's "The Uprising":
Heavy metal makes EVERYTHING better.