I wonder how they will get around the challenge of cross-compatibility. If the device is running anything but Android I imagine the games would need to be built for the specific platform (like how Steam is available for Windows, Mac and Linux but the game selection depends on what is compiled for your OS).
I just bought the 16GB Ouya and would have easily paid ~$70 more for the Tegra 4 and MicroSD support. $120, not so much, but definitely $70. Especially with all the Ouya games coming to it.