There is rather a big difference between a board and a consumer product. Most people are not keen on building their own system from scratch - and so far there isn't another 99$ game console out which is pretty much what OUYA seems to be about. Not to mention a console specific software stack. The fact that there is really hardware already around for that price makes me rather optimistic that OUYA isn't just the dream that never can come true which was my biggest fear for it so far (although I worry more about it's software stack).
Maybe there will be Asia clones ones it's out and a success, but so far there aren't. Someone has to be first...
And if it can get even cheaper in the long run with that hardware - that's also not exactly something speaking against it.
You got maybe a point with the games, but even there I'm not too worried. I don't need lots of good titles for a console - give me a handful of fun titles and I'm fine. Even playing supertuxracer on TV would already be enough fun for me to consider getting it :-)