Indeed, that's the idea!

Docker is awesome for what it does (and I'm extremely happy that they are forcing the Linux containerization stuff to improve, because Sandstorm uses the same features), but to really make per-user (or, better yet, per-document) containerization work, we need to change the programming model a bit. Lots of stuff that every app does itself currently (authentication, sharing, OAuth) really needs to be pushed down into the platform, which is what Sandstorm is doing. And, of course, it needs a UI friendly enough for non-programmers.