You know what would be awesome? If kids learned to code on and tinker with Raspberry Pis. They could learn to code, turn them into robots, do all sorts of cool things. If a few break, no big deal, a 35$ pi is a drop in the ocean compared to how much schools spend on Macs...
For mobile, Firefox OS seems to be the only choice for a truly open platform, and it doesn't hurt that Javascript is the single most accessible programming language to learn (in that you don't need to install anything, just fire up a browser and a scratchpad).