In an interview with the New York Times, Google's VP of search products and user experience, Marissa Mayer, said, "The big insight of Google wasn't text ads; it was that the ads should be conducive to the format. We were doing text-based search that was all textual. Visual ads don't work in that format. With universal search, something is getting shaken up a bit on the bottom part of the page. The ads on the top part of the page should match."
That means video. But it won't be intrusive and blare out at you like some ads do. Google has been slowly incorporating a plus sign into its ads to indicate that more content or information is available. With the new system, that plus could also bring up video content, or Google may go so far as to stick a thumbnail video in there to to indicate that video content is there. But everything will be relevant.
Said Mayer, "We don't want all sorts of video and banner ads all over the site all the time. People who advertise a movie want to show a trailer. Why shouldn't they have the same format we use for search results and have a little plus box that says watch the trailer? If you search for golf clubs, you get ads for golf clubs, not a banner ad about Pepsi that you may drink on the golf course."
For now, the system is just being tested. Google began serving up the new video ads last week. I haven't seen any yet, but the inclusion of video ads will grow slowly to start.