Google officially announced today that they are starting a TV Ads trial.

Together with EchoStar and Astound Cable Google wants to deliver better ads to viewers and help advertisers, operators and programmers more efficiently buy, schedule, deliver and measure ads on television.
As part of this trial, we will be working with partners to use aggregate, anonymized set-top-box metrics to deliver timely and accurate viewing reports. Advertisers can use this data to understand the effectiveness of their TV ad campaigns and use this information to provide more relevant ads to viewers.
More details in this Google press-release.