Bene, finalmente potremo mandare in pensione DIME...
Basterà aspettare WSE3 e/o Indigo... 
As of today, we finally have a W3C recommendation for how to efficiently
encode binary data in an XML Infoset (XOP), and a SOAP binding for that
encoding that's based on Multipart MIME framing (MTOM). Congrats Gudge and the
rest of the XOP/MTOM crew! Our product team is really excited about this spec,
and it should turn up in our products pretty soon - Indigo beta1 and the WSE3
beta will both have support for MTOM.
Fonte: XOP and MTOM are Done!