InfoPath stores its forms in an XML doc within a list item. With that in
mind, you'll probably have to write some custom code to get it into SQL
Server in an unencoded form. There might be some third-party workflow apps
or actions that would do that for you; you'd have to check around.

Another option might be SSRS or SSIS, but I'm not sure about the boundaries
of each of those.

You could also potentially use property promotion combined with either a custom
workflow or event handler to do the push to SQL.

I had an issue with property promotion that the original poster might also run
into. I have a form  with rich text fields, but when promoted they only seem to
be available as plain text. This limits their usefulness in showing views of the
data on web pages. Am I doing something wrong, or is this a limitation of
property promotion from InfoPath forms?

Yes, it is this a limitation of property promotion from InfoPath forms. We've
done extensive research on this (from a non-developer perpestive). However, we
hired consultant Qdabra to provide us with "print views" of specified fields
from a form. They are VERY reasonable and professional. Of course, we knew
EXACTLY what we wanted before they began.