Yes!
I've really wanted some feature like this for a long time. My collection is mostly classical, so the Composer tag is very important, but the iPod doesn't display it (though it's willing to include it in the things to search by). So to see it on the pod, I have to cram it into one of the 3 existing fields that suffice for pop music, but I really hate to mess up my tags like that, when MC gives me so much power to organize properly.