Derrick for sure has the potential for great things. His main problem is he's been slightly injury prone. He had at least one minor injury that set back his training senior year which slowed him down, and this year he had achilles and IT band problems. If he can get a multiple year healthy streak like Rupp, then I see no reason he can't at least match Rupp's accomplishments, and by 2015 or 16, perhaps start to surpass them.
But as nearly ALL our elite American runners know (Hall, Ritz, Solinsky, Teg, Fernandez, etc.), avoiding injury is no easy task.