Question on grounding

Dear all,
 
I have been observing examples on DAML-S and other implementations for a
while. I have some observation that I would like to ask for your opinion. 
 
1)       I realized that almost all the examples available now, all the
input and output of any remote methods to be invoked by the web services are
in primitive types. Setting aside the problem of interoperability of
serialization in each environment like java or .NET, in the semantic level,
how would we be able to describe complex type data like String[], DataSet,
ArrayList. Because the semantic and data structure of these rich data types
are encoded by the developers and it is extremely difficult to describe
semantics of these data types. Therefore, I'm not really sure about how we
could use these rich data types in the semantic web service framework. 
2)       Following the first observation of mine, I was thinking of one
possibility, although impractical, is that we might end up with
implementation of another layer to transfer every data type into an xml
description with semantics before we actually do serialization. Then the
question that comes to my mind is that we lose a lot of promise that the OOP
provides us about reusability of types since at the end everything being
sending through the wire is a document-centric messaging rather than
data-centric messaging. 
 
I am wondering whether there has ever been anyone who address these problems
before? If anyone could share with me your valuable opinions, I would be
really appreciated. Thank you.
 
Sakda