On Friday, we uncovered the new UI for Netflix on Android, days before it was to go live for the world. Today, Netflix made the new phone UI official, and even created a video to talk about the added functionality, look, and new feature set. Once your device is showing the new UI, you'll be able to quickly resume unfinished shows, double tap to watch new shows in an instant, search from anywhere in the app, and filter by more categories. This new look matches up nicely to the tablet UI while also bringing the app into 2012 and out of 2009 styling.
As far as we know, there isn't an update that will trigger the new look. All you need to do is install the app and it should start showing up.