This isn't much of a use of Minecraft, but just to get started I was thinking of using it to teach area and volume. It's a concept I have to get across, and I think the kids would have more fun with something like "design a house with a volume of 100 square units in Minecraft"than "complete this worksheet on volume."
I'm also thinking about using it for social -- maybe something like "design what you think the meeting place for Athenian democracy would have looked like?" The problem for me is that I only have access to the PE, and even that I only have the full version on my teacher iPad. The kids just have the lite version on theirs, and it was a battle to get that much. So if anyone has great ideas, I would LOVE to hear them.
Don’t do work that just exists within your classroom... do work that changes the world. -Will Richardson