If they have the budget--I would change out the black tile and molding and put stone or tile work up the column above the fireplace. If they moved the TV to the right that could work.

I agree with Lauren. I would remove the black marble and white trim surrounding the fireplace (including the marble on the floor). I would then install veneer stone all the way to the ceiling and exactly in line with where the white molding used to be. As long as that is a gas fireplace (which it seems to be), they do not need to re-install a hearth. I would then centre the tv and speakers on the painted wall to the right. I would re-paint the wall in a more subtle shade.