Ramin Djawadi scored the atrocious music for Iron Man, and fortunately director Jon Favreau had the good sense to replace him with the composer who should have scored the first film, a man by the name of John Debney, composer of such films as The Passion of the Christ, Zathura and Elf. This will be Debney's third collaboration with Favreau.
http://www.aintitcool.com/node/41712
http://www.aintitcool.com/node/41712