Yup :) — We are aiming for the Google Docs sharing model eventually. It is specced out and we are slowly implementing it bottom up based on current use-cases.

I'm more the frontend guy at Hoodie, but what you'll be able to do is to allocate roles to users and based on the roles you can give read/write access down to document level.

If you have a specific scenario in mind, I'm happy to elaborate.