Dominaria Spoiler Digest - Who's Who and What's What from the Release Notes
The Great Aurora
Each player shuffles all cards from his or her hand and all permanents he or she owns into his or her library, then draws that many cards. Each player may put any number of land cards from his or her hand onto the battlefield. Exile The Great Aurora.
6/22/2015 The number of cards you draw is equal to the number of permanents on the battlefield that you shuffle into your library plus the number of cards from your hand that you shuffle into your library.
6/22/2015 A token is owned by the player under whose control it entered the battlefield. Tokens shuffled into a library count toward the number of cards drawn, though they cease to exist upon becoming part of a library. Regardless of what you’re using to represent tokens, you won’t shuffle that physical object into your library.
6/22/2015 If a player is required to draw more cards than his or her library contains, that player loses the game. If all players lose the game this way, the game is a draw.
6/22/2015 As The Great Aurora resolves, first you choose any number of land cards in your hand to put onto the battlefield, and then each other player in turn order does the same. The lands enter the battlefield simultaneously.