In May, according to a Nielsen report, 15 billion videos were viewed online, surpassing April's record of 14 billion. Online video reach in the U.S. tops 145 million, and number of streams per month up 2% that month. There also seemed to be a small trend towards longer-form videos. For me, the surprise was the two newer services (uStream and Justin.tv) which allows users to share their own streamed content with the world.
Source: "Video Viewing At Record Highs", VidBlog