Remember when Xi3 announced a Kickstarter project for its modular computers late last year? Well, those machines are here today at CES, thanks in no part to some lofty backing from Valve. We got a first look at its latest mini-PC, code-named Piston, tonight -- and though a more comprehensive demo is to come, we walked away with some impressions nonetheless. Of course, Valve wouldn't back this system if it didn't have some serious graphics chops. It's optimized to run Steam -- and specifically big-picture mode -- and to that end it packs a quad-core chip. Most specs remain vague, though the Piston apparently offers up to 1TB of storage. The package is tiny yet rugged, with an aluminum chassis