Suppose he had died. Effect on art history? Probably not much. He had already painted the famous surrealist dreamscapes which were to be his most influential work. But in recent years his later "classical" and religious works, once generally despised by critics, have undergone a reevaluation: see http://www.surrealismcentre.ac.uk/…/Late%20Dali%207.9.11.pdf for example. ("As North American art history and theory move further away from modernist paradigms largely defined by Greenbergian formalism and Breton-style ethics, the later work Dalí produced which had been quietly written off as embarrassingly reductive, commercial and gauche, begins to look surprisingly vanguard.")