it seems Autopilot will be disabled when you're not doing freeway driving, which is by far the easiest aspect of autonomous vehicle activity. Musk did confirm that the Autopilot mode would be "technically capable of driving from parking lot to parking lot." The car will also be allowed to drive itself when you summon it, and when you're parking it in your garage.
A great review of the self-driving car solutions, with links to other articles on the subject.