[kohsuke]

I always thought a better way to combine programming & minecraft for kids would be something like ComputerCraft (http://www.computercraft.info/), where you can program a robot inside the Minecraft world to do stuff for you, like building road/bridge, digging tunnels, etc.

ComputerCraft is Lua-based, but I can imagine something similar based on CLR, and that way you can let kids program in C# from Visual Studio.

Programming a bot is much simpler and even a very simple program (like digging a tunnel straight) is instantly gratifying. Writing a mod has a much higher barrier to the entry, AIU.