To understand the degree to which technology for handling attachments is still a work in progress, we can look at other emerging specifications to see how the industry could evolve . DIME certainly doesn't come without problemsincluding the routing and security of DIME-based messages, both of which are difficult to handle within the existing specification.
One of the most recent specifications at the time of this writing is PASWA (Proposed Addendum to SOAP With Attachments). This specification, which is based on the original SOAP With Attachments specification, is coauthored by AT&T, BEA, Canon, Microsoft, SAP, and Tibco. Draft v0.61 of the specification can be found at: http://www.gotdotnet.com/team/jeffsch/paswa/paswa61.html . In short, this specification uses MIME and a superset of the original SwA headers to allow messages to be properly secured and handled by intermediaries, to ensure backwards compatibility with SwA/1.0 messages (which are in use today), and to provide an alternate message syntax for SOAP processors that do not understand the specification.