There was recently a very long thread about this, something about best micro atx board for games- either I can't find it or it dropped thru the cracks of the search engine.
Anyway, there was a lot of talk about the soltek micro boards, both with and without integrated video. There's also a favorable review at viahardware. These use the "133a" chipset, and have all the performance options.
Here
Review
Right now, I'm encountering some difficulty on the home front about moving yet another new computer to the top of the priorities.. otherwise I'd be able to say how well one actually works....
And yes, I think that microboxes are the wave of the future, for mainstream pc's, anyway. Transistor radios were the size of a fat dictionary when I was a kid, now they fit on a single chip, in your wristwatch.... It's inevitable. In ten years our current boxes will be described as behemoths...