According to Brian Womack, Nick Fox, a director of business product management at Google, also claimed, Its clear that this is something that users want.

It ties back to trying to understand what a user is doing on Google, what an advertiser is trying to sell and matching those up.And indeed, it makes sense that someone searching for info related to the movie Extract would want to see the trailer.These experiments may well be deemed a success and turn into something more permanent, then. But given the 18month thinkitover period thats already passed, no one should hold his breath.