It's ... smaller than I thought it would be. The LEGO Minecraft Micro World (fitting name!) will be shipping this summer. The 480-piece set is being sold exclusively through Jinx for $34.99, and they're already taking orders. Seems expensive, but I suppose LEGO isn't exactly known for being cheap.
I have to say, the mini Creeper is probably the best part of this. If you're looking for more to go on, check out Mojang's silly video skit.