I think that the curtains would be lovely if the wall wasn't so dark. Perhaps paint the wall a cleaner, airier, less muddy color and the granite will complement rather than dominate.

Whatever you decide, it looks like you have a great start! Also, I realize this wasn't part of your question, but I think some crown moulding would help balance the trim on the fireplace mantle and make the room appear more polished. Good luck!