Oracle Text

Whenever another nontoken artifact enters the battlefield under your control, you may pay 2. If you do, create a token that's a copy of that artifact.

Card Rulings

6/1/2011 Each time the ability triggers, you can pay only one time to get one token.
6/1/2011 As the token is created, it checks the printed values of the artifact it’s copying, as well as any copy effects that have been applied to it.
6/1/2011 The copiable values of the token’s characteristics are the same as the copiable values of the characteristics of the artifact it’s copying.
6/1/2011 If the artifact that caused Mirrorworks’s ability to trigger has already left the battlefield by the time the ability resolves, you can still pay . If you do, you’ll still put a token onto the battlefield. That token has the copiable values of the characteristics of that nontoken artifact as it last existed on the battlefield.