Impressive. And now I'm wondering if a Minecraft inside Minecraft would actually be realizable. As 8bit CPUs have already been made (altough with unknown architecture), it is a bit less crazy to imagine running linux with a java stack on it. It will be hellish slow and you probably need some sort of "hardware" graphic acceleration. And a lot more memory than the current versions. But hey, running Minecraft in Minecraft would be pure brainmelting awesomeness!

Maybe some sort of Hardware Description Language to Minecraft compiler would be useful.