I think the authors of this article are either out of touch with reality or working for computer manufacturers.
http://tinyurl.com/4w98yaI wouldn't entrust a laptop to a kindergartner no matter how much it weighed. The kid can't read or write, but you're giving them a multipurpose general computing device? Teach reading and writing with paper and pencil first. Then when they have the motor dexterity to use a pencil, introduce them to the keyboard.
When the time comes to put a computer in a kid's backpack, here's how I see it working. Assignments in the early elementary school grades are very targeted, with specific rules and expectations. Why shouldn't the kid's computer be the same way? They can't take their paper math assignment and use it to play with Pokemon without some legitimate creativity. I envision an elementary school kid's laptop with a small screen, small keyboard, enough flash memory to store an assignment with video, meager general purpose computing power, and GPU for powering video. The teacher would load the day's assignment into the flash (no operating system = big savings!) via wi-fi, and the computer simply wouldn't have anything else on it. (Again, no operating system. Just the assignment.) Sturdy case material, no moving parts, low-power everything. You could absolutely mass-produce that for $100.
But first, pay me for my $0.02.