Prolific bestselling thriller author James Patterson, who caused a stir a year ago when he jumped from longtime agent Richard Pine to Janklow & Nesbit, has made another leap--to William Morris, where Jennifer Rudolph Walsh is putting together a team, following the Hollywood example, and working closely with the agency's West Coast staff, to package his present and future product. She said that her team, which includes WMA's Joni Evans, will be looking at movie possibilities for Patterson "at a new level appropriate for a client of this size." At this stage, the talk is mostly of new film possibilities; Patterson still has some way to go on his last Little, Brown book contract.