Valve decided to make their own TV commercial for Portal 2. This was because, said marketing VP Doug Lombardi, "We’ve had many creative kick-off meetings with agencies over the years, and you’d be shocked by the treatments that have come back. Copycat treatments. Cliché treatments. Treatments that reveal the agency wasn’t listening in the initial meeting." So instead Valve opted to make their own advertisment, in an eight week project.
It's cute. And embedded below. The game is out in the 21st of April.