Mike Wilson has taken pity on all of the modders who have been chomping at the bit to get their grubby hands on the SDK. He has just announced that Volition will be making all the alpha modding tools that we have all been working on publicly available! This includes many of the command line tools and full documentation on all the lua functions.
Please keep in mind that this is NOT the sdk, and does NOT include any of the 3ds max plugins yet. These are simply alpha tools in a very rough state that are being released so that the community can play with them. Look for the alpha release and public github repo to go live early next week!