How soon until this can replace Dropbox for my little distributed working group consisting of 3 people wanting to share a single file system?
Take a look at the "mounts" section of the blog post where we describe a group pattern you can set up. You can create a group directory called "team-drive", then mount each user's drive into the group.
If you're using FUSE, this will feel similar to Dropbox, but with one directory per-user.
We're starting with these kinds of simple mounts, and brainstorming ways to extend them soon.