For a while now you’ve been able to pair your various devices with the PS3 Youtube app, which means you can access your subscriptions and saved videos on the big screen. It’s a fairly straightforward process that starts by starting the app up on the console, and then entering a code. Now it appears you can stream your purchased Play movies to the PS3 by selecting them on your device and activating streaming, without having to spend money on a Chromecast.
I’ve tried it using both my laptop and smartphone through the Youtube website and app, using the free Big movie purchase from a few months back, and it works fine. I’ve been looking around and it appears a few users already had access to this but it is rolling out to more people. Google hasn’t really publicised the feature that much. You can’t stream your music purchases the same way, though there are third party apps like Skifta for smartphone that are compatible with the PS3 and allow you to do it.
Source: Tip from Mark (m6176b on Twitter)