Welcome to the QB, Ogle! Your curiosity is a breath of fresh air today in our hot, sticky weather.
I know that exposed W&N works very well for both wall quilts and art quilts, though I'm not at all sure it would stand up to the frequent washings of a bed/utility quilt. I'd love to see your experiments!!
It has been used frequently, dyed or painted, as an outer surface by some art quilters. A few examples:
http://judyperez.blogspot.com/2008/1...-with-rit.html
http://paintedthreadsprojects.blogsp...g-batting.html
http://approachable-art.blogspot.com...art-quilt.html
I know I've seen it just plain 'au naturel' as well, but can't seem to find any appropriate examples for you. Sorry.