At the beginning of each player's upkeep, that player chooses artifact, creature, land, or non-Aura enchantment. All nontoken permanents of that type phase out.
"Fire is dead. Water has killed him." —From The Stories of Nature
2004-10-04
Does not affect token permanents, only cards.
2005-08-01
Can affect itself if you choose "non-Aura enchantment".
2008-10-01
This has the supertype world. When a world permanent enters the battlefield, any world permanents that were already on the battlefield are put into their owners' graveyards. This is a state-based action called the "world rule." The new world permanent stays on the battlefield. If two world permanents enter the battlefield at the same time, they're both put into their owners' graveyards.