How so? Ouya isn't going to attract big name developers creating exclusive new IPs just for the console. That is a laughable pipe dream. The main content for this console will come from the Android Market place the place you can access for free and download to ANY Android device. All Sony or MS would have to do is include a software Android emulator, similar to what you can install on your PC and then their is nothing stopping the PS3 or XBox from going to the Android Market and downloading and playing the content that is on there. No license fees or issues and with the added bonus that the content on the site does not FORCE developers to provide free to play content.This isn't really my area, but I'm not sure it'd be that simple. A big part of Ouya's sales pitch is that they aren't going to hit developers with licensing fees or related costs. Also, all games developed for the console will be required to have at least some free bits (which can mean partially free-to-play, microtransactions, and so forth), and I imagine that luring loads of those games to the 360/PS3 would mean radically shaking up some business models.
The reason why Android market is great for developers is because they can develop a game or bit of code and it will run on millions of Android devices irrespective of who makes the device, no developer who already works with Android is going to jump ship from that market and start developing just for the Ouya, so in essence that means anything that appears on the Ouya is logically going to appear on the Android Market and thus can be played on just about any Android device including a console by a big name rival running an Android emulator.