Ever since it popped up this morning, people have been quick to say that Aaron Bishop's Lords Of Uberdark looks a lot like Minecraft. The fact Minecraft's creator helped spread the word may have contributed to that.
While Lords Of Uberdark (which at the moment is little more than some alpha code and ideas) is in the same mine/craft guise as...Minecraft, there's one key difference: it's not based around blocks or tiles. It is instead free-form, your ability to edit the world being far more natural than something which ends up looking like a giant LEGO set.
I'm also digging the art style, the bright colours and stark lines invoking memories of Okami.