This was much easier than i thought...
So, there is now a 3D coordinate grid to walk around on, made of blocks. And blocks can now be seen in a field of vision. Right now, the field of vision is:
y+3, and x +/- 2
This will be extended significantly, but right now, there's a basic command to add blocks to the world, and the blocks move in and out of visibility. Haven't coded in occlusion yet, but it shouldn't be really hard.
I decided to go with ZODB, just because it is so very easy to use. I may code in support for MySQL later. We'll see.
I'm also going to open up the bitbucket repo for anyone to clone, in case they want to check out the code.
Be warned: my focus is on functionality, not neatness right now.
I think I'm going to end up coding a custom object builder using Panda3D or somesuch. I'm thinking a text only interface might be really difficult.