Place quartered pears in 2-quart saucepan. Add pomegranate juice and granulated sugar (if pears are not completely submerged, add more juice and sugar). Heat to boiling. Cover with lid slightly ajar. Reduce heat; simmer 20 minutes or until pears are soft when pierced with fork.
Meanwhile, grate peel from oranges; set aside. In large bowl, place mascarpone cheese. Cut oranges in half; squeeze juice over mascarpone in bowl. Using electric hand mixer on low speed, beat until well blended. Add grated orange peel, whipping cream, powdered sugar and gingerroot; beat on low speed until combined. Increase speed to medium; beat until soft peaks begin to form.
On each dessert plate, place 2 warm pear quarters. Spoon whipped cream over top.