7PM This episode's headline: News Summary; Road to the Summit; Superfund: Making a Difference?; Miami Vice: Beautiful But Dumb?. The guests include In Washington: LESLIE GELB, New York Times; DIMITRI SIMES, Carnegie Endowment; ARNOLD HORELICK, Rand Corporation; LEE THOMAS, Environmental Protection Agency; In Philadelphia: Rep. JAMES FLORIO, Democrat, New Jersey; Reports from NewsHour Correspondents: ELIZABETH BRACKETT, in North Carolina; JUNE MASSELL, in New Jersey; BILL BAROL (Newsweek). Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor