Robin Williams will soon undergo heart surgery, People reports. The 57-year-old entertainer, who needs a new aortic valve, has canceled performances of his one-man show until at least the fall. He entered a Florida hospital this week short of breath. "I'm so touched by everyone's support and well wishes," Williams said. "This tour has been amazing fun and I can't wait to get back out on the road after a little tune-up." (More Robin Williams stories.)