Just one day after Spore got its final release date, EA announced that the creature editor will be released before that.
EA didn't reveal any more details regarding the editor's pricing and release date, but we expect it to be released in July or August for free or, more likely, as a preorder bonus.
Although spore is strictly a single player game, all its content will be players-created. Every creature you'll meet in your single player campaign will be completely designed by another player. Player generated creatures will be uploaded to "Sporepedia", a content-driven social network built right into the game.
Releasing the editor before the game is a convenient way for Maxis to populate Sporepedia and build more hype for the much anticipated game.