When a company like Motorola develops a tablet, they contract the manufacturing to Foxconn, so they can't sell it for $400 and make a profit. That's why they launch with carriers first instead of selling wifi versions to consumers from the outset. They can sell thousands to Verizon up front, but they're probably just break even the moment they start selling unsubsidized versions in Best Buy. Apple also contracts to Foxconn, but gets better margins due to economies of scale (they're projected to sell, depending on your source, between 20 and 60 million iPads this year) and a higher lifetime value per customer vis-a-vis the App Store, iTunes and iBooks.There is obviously huge support for a tablet in the $400 range. I'm not sure why no one is working on something in this range! I hope this is it. Otherwise, me and a bunch of other people will continue to wait on the sidelines until something affordable comes along.
-Brian