At the Web 2.0 Expo, we asked Tim O’Reilly, Dan Farber, Matt Mullenweg, Jay Cross, Brian Solis, Kevin Marks, Steve Gillmor, Jeremy Tanner, Maggie Fox, Tom McGovern, Sam Lawrence, Stowe Boyd, David Tebbutt, Dave McClure, Chris Carfi, Vamshi Krishna and Rod Boothby the same question: “What is Cloud Computing?”. Here’s what we got.