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ET was at the star-studded screening of Matt Damon's new documentary in New York City on Thursday night, where the star shared his thoughts on the news that Oprah Winfrey plans to end her show in 2011.

"I just heard that and I'm shocked…," Damon said of the news. "But I'm sure that whatever she does will have a lasting and positive impact on American culture. She's just an incredible human being, and I don't think she's going to disappear. It would be amazing to not have her in front of you every day in your living room…I still have to digest it. She's done quite a bit, to say the least, over the last 25 years. She's got to do what feels right for her. She's certainly earned that right."

Matt also told us about his new documentary, which is inspired by acclaimed historian Howard Zinn's A People's History of the United States and executive produced by Damon, Josh Brolin and Howard Zinn, among others.

Marisa Tomei, Viggo Mortensen, Sandra Oh and other stars recreated important moments in history for the documentary, which celebrates the spirit of democracy.

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