In my opinion, its all realitive, anyway. A standard cellphone produced in 1997 had more than 2000 times the processing power of the computers in the Apollo lunar capsules that made it to the moon and back. While its true that the Tegra 3 cores aren't as powerful as some others that are available out there, the Android OS is much like the Java of operating systems. Generally low-key and not very resource intensive on its own, meaning it can support higher ranges of programming that require more.
Also, most people here are missing the point about the hardware specs to begin with. Consoles, reguardless of their make or model, specialize in low RAM, but generally high processing power and high graphics; when compared to computers that have high RAM, medium processing power, and (mostly) low graphics. The hardware wouldn't be too much of an issue, given that fact. Plus, if the Ouya console itself can be opened and modified, it just means people could install their own upgrades and stuff to it, and could end up opening the whole system up like the PC market when it comes to customizable hardware. Not nessissarily a bad thing.
The only bad thing I really see about it is the support and interest from the big-name developers. With the consoles being so cheap, the creators of OUYA will have to make their money by selling the game developement rights with their hardware, which is easier said than done when everyone else is strictly interested with brand-named POS' like XBox, PlayStation, and Nintendo. Not to mention the sort of legal troubles they could get if people start trying to port popular games (MineCraft, ect.) to OUYA as third-party products that go against trademarks.
All in all, I just want to sit back and watch to see how it goes for right now.