Hi, just throwing out some ideas on the block registering API.

1. Currently block types are created via wp.blocks.registerBlock( slug, settings ) which returns the block and also adds the block as a key, value pair to the somewhat global blocks. This is a coupling that I do not think should be made. I would recommend the creation of a block to be handled in a function blockType( slug, settings ) ( or preferably just settings ). Then the registry of blocks can be another factory function that creates registries of blocks, which can have the method registerBlock( block ) on them.

This will make testing a lot easier/cleaner and will also create a bit more flexibility in the code for unforeseen future needs.