This is a really cool idea. I feel like to some extent, however, you would likely get the disadvantages of both commercial & homebrewers. Would you have to deal with all the taxes & licensing issues that come with selling alcohol, as well as the federal restrictions on homebrewing quantity?
There's a guy in NY who runs a wine CSA, http://www.enlightenmentwines.com/CSA.html
. I'm sure he could answer some of these questions. Let us know what you find out either way. This could be a very interesting way to get good, local, experimental beer out there.