Text (RV+errata): You may have ~this~ enter the battlefield as a copy of any artifact on the battlefield. It's still an enchantment. [Oracle 2009/07/08]
Note - Also see Copying Objects, Rule 706. There are enough important rules there that they are worth reading first.
The artifact to copy is chosen at the time this card enters play. If there is no valid artifact to choose, then this card enters play as a global enchantment that has no effect. [D'Angelo 2001/08/31]
As a copy, Copy Artifact copies all initial characteristics of the targeted artifact. This includes name, abilities, whether or not it is a creature and more. [CompRules 2001/07/23]
The copy of the artifact is not still blue. It copies the color of the thing it is copying. [Duelist Magazine #14, Page 26]
The copy is both an artifact and an enchantment, so it is an artifact-enchantment (perhaps even an artifact-creature-enchantment). It can be affected by anything which affects either type of permanent. [D'Angelo 1994/06/01]
Vintage tournaments (see Rule 911) restricted this card from 1994/03/23 to 1997/10/01.
Legacy tournaments (see Rule 912) banned this card until 1999/04/01.
Extended tournaments (see Rule 913) have banned this card since 1999/10/01.
Standard (Type 2) tournaments (see Rule 914) have banned this card since 1995/05/02. It was previously restricted up until 1995/05/02.
