I'm pretty sure OUYA will not have access to the Play Store officially, and they will have their own store, which should also filter out all the apps that aren't specifically made for the TV experience.

So this is more like an "Angry Birds is coming to Kindle Fire" thing. Just because it's compatible, doesn't mean it will be available out of the box, if it doesn't have access to the Play Store, and since it's a much different form factor from phones and tablets, the interfaces will need to be changed quite a bit.