(I am now concentrating on doing the same with VML as that is more or
less
equivalent (except for the great SVG filer capacity) and MS will not
start
with SVG for some time (Office 11 with VML/no SVG).
I seem to remember reading that the next edition of Visio should have
SVG export.
If Office 11 allows one to create documents based on XSDL then it should
be possible to have a schema that allowed at least a subset of the svg
namespace in a particular document type. But of course that is SVG
output, not SVG input.
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list