XML DSig, XForms & WYSIWYS

It seems that one of the core features of XForms is that submitted
data may be in the form of an XML structure.

Superficially this appears to be ideal for adding an XML signature.

However, is if a goal is to achieve What You See Is What You Sign
(WYSIWYS), things get more complex as the submitted data only
constitutes of a portion of the actual view (which BTW may contain
embedded objects including graphics).

Comments?

Anders Rundgren
Working for a major US computer security company but here acting as an individual