Sideloading on the shield works fine (it loads it as a new app though, it doesn't overwrite the stock vudu app). I was able to log in to my account and access my library. Only tested in the bedroom though so wasn't able to test 4K/Atmos audio.
it shows non-compatible with Sony Android TVs...
Work on Fire TV?
Hm. The app shows non-compatible with the Nvidia Shield. Wonder if we'll get some of that sweet Material Design love.
I can't complain; at least we've been able to use Vudu.