I have no interest personally for obvious reasons. I know a few people who might be interested in windows hosting - but you haven't said what you might be offering in this area.
Just as a side note - Most of the people I know who use hosting sites
are interested in their own IP - and are
not interested in loads of e-mail addresses. Dunno if that is common or just the type of people I know.
If you ever plan to offer dedicated windows servers in the uk drop me a note