I received my OUYA last Wednesday (3 July).
The hardware is gorgeous, although first impressions weren't that great due to the long time involved with setting it up for my home network, and then the need to update the firmware.
Plus, I had to learn how to use Android a bit, since I had never used any Android devices prior to this.
I checked out the demos for
Chronoblade and
You Don't Know Jack. Graphics are easily on par with the iPad, or even early PS3 games. However, the biggest strength of the OUYA is emulator support.
There are emulators for NES, Super NES, Atari 2600, Nintendo 64, Commodore 64, NeoGeo, and PlayStation in the app store. Plus, sideloads for CPSemu and Retroarch are supported.
While the OUYA controller is rubbish, connecting my DUALSHOCK3 to the OUYA was relatively painless

Can connect ds3 so many emulators...
now u make me wanna get 1 even more....