When I was there about a month ago, the posted closing hour was 11 PM, but most of the shops in Main Street stayed open for a while. I think we actually left the park a little after 11:30. All of the rides and attractions did close at 11, though, and I think people were asked to leave the "lands" other than Main Street. Some of the merchandise shops did start to close (e.g. only a few registers open, some closed all together) a few minutes after 11, but all of the shops that sold food, and those that sold more guest-service type merchandise (e.g. phone cards, stamps, film, batteries, etc.) were still open at 11.