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, 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 at the same time, they're both put into their owners' graveyards.