Yes, we're very much aware that AC/DC actually recorded this song back in 1980. Originally on Back In Black, it's one of the band's signature tunes. Along with 14 other AC/DC tracks, it'll be on the soundtrack for Iron Man 2, which is due out April 19.
This is the second time AC/DC's been used to soundtrack a movie. Hopefully, this will turn out better than Maximum Overdrive -- which, coincidentally, also featured a Marvel Comics character (the Green Goblin) as the cowcatcher on a semi truck.