I actually really like Hollywood Undead (the band in the background) but I agree it totaly does not go with the movie. Also, apparently the real musical score is not rock, and they are using 'fill in' music because it is supposed to be so good they dont want to 'spoiler it'. Time will tell.
As to the trailer itself, it looks as to be as close to making Howards stories jump off the page, as Jackson's films did LOTR, and I dont say that lightly. They really look like they have nailed it, and I cannot wait to see this