No, it's a mistake, they should have left the original date. If you update it you are supposed to do year, year, year or a range.
Like coderdude said above[1], whenever you see "All Rights Reserved"[2] you're seeing it in action.
1. http://news.ycombinator.com/item?id=3541501 2. http://en.wikipedia.org/wiki/All_rights_reserved