Like the PS3 version of YouTube, you'll be able to command your Netflix experience with your mobile phone. So long as your PS3 is connected to the same network as your iOS or Android device, you'll be able transform your phone into a nifty remote control.
According to Engadget, you can browse for another movie or TV show to watch and have it play on-screen. You can also stop, pause, scene-select, change audio and subtitles.
The feature is being referred to as an "easter egg" by many, as it's a feature that's likely to go underutilized. Here's a video on YouTube to see the cross-device magic in action: