Google is finally offering a profitable business model to YouTube. Aware that inserting advertising in the anarchic video provider would make users shrink back in discontent, Google temporized, looking for something more adapted than Adwords.
In fine, the ads are going to be in video format (how original), displayed after 15 seconds of viewing a video, in the bottom corner of the screen. Users may click on it to view the entire ad, but can't get rid of it.
The CPM should be $20 square, a high price for advertisers, considering that the ads will be merely shown on videos from YouTube's content partners (about 1000 companies that have licenced their video with YouTube).
Overall, Google made the right move. First it's finally going to get ROI on its biggest investment (aside from Double Click).
Then the ads will only work with content partners, meaning that non-professional users won't see their submitted videos commercially exploited with no shared revenues. This leaves space for other smaller online video protagonists (Revver, VideoEgg...) to attract independent publishers.
My advice for online movie producers: Don't forget there's going to be an ad taking a fifth of the screen on the bottom right inside. Avoid relying on that area for showing anything important (like logo or clip name).