it's a great idea and I would love to put in the OUYA the project I am currently working on or provide ideas and graphics for a new project.
Technicaly, we should be aware that since the DEV kit will not include any browser in it, it's pretty unlikely that the a html5 game will run in it, at least not at first: even if you compile the game you still gonna need a browser to run it.
Recently though I was thinking that in future, a brave and skilled dev could develop a sort of html5 game optimized app (sort of a browser but ''pimped'' like a market place) where OUYA owners can connect and play our html5 games.
Imagine how cool it could be, we will no have any compiling issue and we have just to export the game in standard html5 to have it running on the OUYA.
Since the console it's pretty powerful there is no reason why this should not be possible