Since Wool batting doesn't shrink...
 

what will it look like if used in a top and backing of unwashed fabric? The quilting will be loops and swirls allover.

I used Hobbs wool batting with unwashed fabric. There was some crinkliness but not a tremendous amount. Though I did not heavily quilt it. With heavier quilting, especially with loops and swirls you will probably have some nice puffiness and texture. Here is a link to the pic of the quilt.

http://www.quiltingboard.com/picture...d-t148167.html

I believe both of the best brands of wool batting (Hobbs and Quilter's Dream) shrink up to 3%, the same as most cotton battings. It is polyester batting that does not shrink. As AFQ described, you will get slight crinkling but not a lot. This is actually the look I prefer in quilts.