Courtesy of AppAdvice and Engadget, two videos to get a quick overview of what using iOS 4 on the iPad feels like. I have it, and it's great: apps already updated for the new APIs on the iPhone are working fine on the iPad, some of them (e.g. non-universal apps) are having some issues.
Anyway, iOS 4.2 really manages to make the iPad feel like a new device. And it's just the first beta.