[jsmith45]

Since it uses the Google TV app (previously known as Play Movies & TV) as the data source, it supports whatever that does, which almost certainly does not include Plex or similar.

On the other hand, it probably does support streaming from any Cast enabled app, so it probably won't be any worse than a classic chromecast, even if direct on device content is probably highly limited.

The real question is if it supports installing Android TV apps, to extend the built-in UI or if it is limited casting and the content from the app.

Another screenshot shows a "My Apps" row on the homescreen, so I suspect it might actually support installing additional apps. I tend to doubt they get to integrate with the launcher in any meaningful way though.

Android TV did allow that, but they seem to want to be able to support things like a single playlist across the android Google TV app and the various new Google TV devices.