If you've ever wondered who the heck that actor was, a Play Movies info card might have been able to tell you. However, support was previously limited to the US and a few other territories. Starting today, info cards are working everywhere Play Movies is available.
— Google Play (@GooglePlay) June 3, 2014
These info cards aren't part of Google Now, but they have a similar contextual thing going on. Simply pause the video, and info cards will appear at the edge of the screen with information about the actors in the scene, the film itself, and even the soundtrack.
While info cards are now available worldwide, not all movies in the Play Store have them. And of course, there are still plenty of countries that don't have access to Play Movies at all just yet. Maybe one day.