http://www.ign.com/articles/2014/08/21/xbox-one-now-supports-pre-loading

Xbox One now supports pre-loading, starting with the release of Madden NFL 15.

You can pre-purchase Madden NFL 15 through the Xbox site. The game will then be available to download, but won't unlock until 12:01 AM PDT next Tuesday. Those who registered for EA Access, the Xbox One exclusive subscription service, can access it now. The playtime is limited to six hours.

Microsoft announced pre-loading for select games at its Gamescom briefing. Xbox head Phil Spencer promised the functionality for FIFA 15 and Forza Horizon 2 in September. Spencer had previously promised it was coming during E3. Then in July, Brandon Winfrey from Sunset Overdrive developer Insomniac Games said it was coming "soon."

Sony's PlayStation 4 began offering pre-loading in June.