I do not know what it would take, but it would be great if Plex could be the client to playback my UV content as well as integrate it to my movies library. I'm sure there is too much to it for the feature to happen, but one can wish!
I definitely support this idea. Sadly the UltraViolet system is rather closed and not likely to ever appear here.
However, on just about every platform there is usually an app that can access your UV collection.
Flixster for Android
VuDu is on a lot of Blu-Ray Players
I'm pretty sure that there is something for Apple Devices.
2021 clean-up: duplicate