spike-
As metengr said, a client can specify the use of the 2004 edition for new orders today. As far as I know, we have not yet received our copies of the 2004 edition. However, their nominal date of issuance is probably July 2004, and they are probably being shipped now.
From the Foreward to Div. 1 (page viii):
"After Code revisions are approved by ASME, they may be used beginning with the date of issuance shown on the Addenda. Revisions, except for revisions to material specifications in Section II, Parts A and B, become mandatory 6 months after such date of issuance, except for boilers or pressure vessels contracted for prior to the end of the 6 month period."
So if you issue a PO for a new vessel on December 30, 2004, the July 2003 edition may still be used. Issue that PO on January 2, 2005, however, and the 2004 edition is mandatory.
jt