You will have people who normally travel Sunday nights to get to their jobs on Monday morning, may wait until early Monday morning to fly out to take advantage of the holidays with their families. We have a family friend who flies weekly for his job out of O'Hare and he takes off the entire week between Christmas and New Year's, and takes the red eye out very early Monday morning to get the most out of his holiday with his family.
You may also experience a bit more traffic around the airports. But other than that, most people will have returned home by Sunday due to school schedules and going back to work.