Thorgi Duke of Frisbee

True, but they're made from parts that are manufactured separately and then shipped out to plants where they are assembled into PCs. If they just started making consoles with PC hardware, there are a few spots they could shave the price a bit. Also, they could do it as a loss leader - the iPad has tiny margins, but brings people to the App Store and Newsstand.

They could also take kickbacks for bundling certain software with it, though to your point, that is also something PC OEMs do already.

iPad has a closed market, just like consoles. You can only (officially) buy Apple apps, PS3 games for your PS3 etc. A PC is open, there's no garunteed way to get any cash back on your loss leader. Valve also can't rewrite how PCs are made. As to your second point, Valve would be the ones making certain software. They'd be the one's paying the kickbacks.