Hopefully they'll also include already worlds (1-8 + 9th secret) produced for the game so people can just jump in and play them if they don't want to make any levels, that and, this alone would be a waste of a Blu-ray Disc (BD25) with so little amount of data on it.
I know that goes against the purpose of Mario Maker but it'd be good to feature in the game so that they satisfy the fanbase (last 2D Mario game was NSMBU on the Wii U).