I wouldn't recommend Tegra2/Tegra3 SoC's.

They have proprietary components.
Also they have an internal module that controls the cpu and gpu behaviour. Vastly limiting your control over voltage, frequency and governors.
This is one of the pitfalls of the OUYA in my opinion, it should be 100% open hardware instead. The Exynos4412 would make a fine choice.

Though I'm suspecting the OUYA will be a bad buy, because its almost outdated as A15's will be imminently released this year. And because, even though the 4412 is an exceptional processor, a year from now, when the OUYA finally ships, it won't be.

To add insult to injury, it would be competing and outclassed by the X360, PS3 and WiiU.

edit: If there was any time any way, for an Android console, it would have been:
-Q3 2011, Android 4.0, 1GB RAM, Exynos 4212.
-Or Q2 '12, Android 4.1, 2GB RAM, Exynos 4412.