No, Hierro has stepped in temporarily but he's the Sporting Director. It's feasible the tournament goes well and he gets the job permanently, but Spain don't often plump for inexperience.
I don't think there is any danger of Benitez taking over Spain. His style of football is ill-suited to the type of football they have invested in over the last 15 years. Its not attacking enough or mobile enough. I'd imagine they will target someone like Enrique who has come up in that era.