AC/DC has become a Stark motif, but that's all getting tired and old, just like the band.
Might be nice to bring in some fresher hard rock/metal, to signal a change in Stark's personality and to quit making him be stuck in the past. Something like Wolfmother, Kasabian, Queens of the Stone Age, System of a Down, Disturbed, or even some thrash from Metallica or Megadeth could make him a more hip rocker, instead of a dadrocker.
That being said, I think it *would* be cool as hell at some point to include Paul McCartney and Wings' "Magneto and Titanium Man" on the soundtrack.