UPDATE: StarWars.com has a statement from George Lucas, who says, "The world has lost a great director and one of the most genuine people I've had the pleasure of knowing. Irvin Kershner was a true gentleman in every sense of the word." Other websites, such as Wired's Underwire blog and MTV Movies, have also offered tributes.
UPDATE #2: CNN.com has posted an obituary that includes comments from Billy Dee Williams, longtime friend Barbra Streisand, and fellow director Francis Ford Coppola.
UPDATE #3: Responses continue to pour in and The Official Star Wars Blog has collected some of them. Click here for a post with thoughts from celebrities like Daniel Logan, Katie Lucas, Kyle Newman, Milo Ventimiglia, and Simon Pegg.
UPDATE #4: Continuing to pay tribute to Irvin Kershner, Starwars.com presents a 10 year old interview with the late director conducted by Scott Chernoff from Star Wars Insider #49