Thanks for Martin's input.

Hi Juan,

As Martin has said, XML Webservice is mainly focus on Data transfering, and
the transfered data objects are represented by plain XML. Also, most of the
data objects should be conforms to a certain XML Schema. As for COM object,
it is platform dependent and contains much internal data and structure
which is specific to the COM runtime, so it's hard to represent such
objects through plain XML content. If your application is going to
communicate through COM object between client  and server, you may consider
COM+. For webservice, it may be capable of transfering some lightwight data
such as the COM object's CLSID, remote COM server's name and address....

Regards,

Steven Cheng
Microsoft Online Support