http://www.engadget.com/2013/11/08/xbox-one-day-one-update-details/
"Functionally, you will be able to do very little without taking the day one update," Microsoft senior director of product management Albert Penello told Engadget in a recent interview. We posed just such a scenario to him, and asked what we could do with an Xbox One out of the box. "Nothing. You need the Day One update," he said.