In a small saucepan, mix together 2 tablespoons sugar and cornstarch. Stir in orange juice and pomegranate juice. Bring to a boil over medium heat, stirring constantly, until sauce thickens and is clear. Cool to room temperature, then refrigerate at least 1 hour.
(Optional: Crisp up the fillo shells in a preheated 350° on a baking sheet for 3 - 5 minutes, until golden browned and crispy. Remove to a wire rack to cool completely before filling.)
In a small mixing bowl, beat together cream cheese, sour cream, 2 tablespoons sugar, mandarin orange juice, and orange zest until smooth.
Fill each shell with the cream cheese mixture. Top each with one to two teaspoons of mandarin orange topping. Garnish with an orange slice and a cherry on a skewer.