Custom blocks are a problem when it comes to deployment. You create them locally, and then you have to re-create them on the production server manually, sometimes worrying about getting the same IDs as the original ones.

I want to be able to create some custom blocks on my local server, then create a Context that is associated with them. In the Context I want to have a checkbox that asks if I want the custom blocks to be considered as new blocks in the system (single checkbox for all custom blocks in the Context, or one checkbox per block - what do you think?).
When I export my Context, or add it to a Feature, the custom blocks that got checked this way will get the ID 0, and their content (title and body) will also get exported.
When I import my Context, or turn on the Feature containing that Context, custom blocks with ID 0 are created as new blocks and associated with the Context.

I'd love to hear you thoughts. I know there are active projects that are trying to do something similar specifically with Features (e.g. Features extra), but I believe a Context solution will be much more comfortable.