Great little app called Christmas Ringtones is in the Marketplace. It’s free and lets you set Christmas songs as your ringtones which include:
Jingle Bells; Silent Night ;Deck the Halls; Oh Holy Night; Sugar Plum; Joy the the World; Good King; Christmas Tree; First Noel; 12 Days of Christmas; Angels We have Heard; Away in a Manger; Christmas Tree; God Rest Ye; We 3 Kings + many more !! PLUS REMIXES Also! We included REMIX versions of your favorites in Hip Hop/Electronic styles.
You can check it out here.