Heat oven to 350 degrees. In large bowl, combine sugar and butter. Beat at medium speed, scraping bowl often, until creamy (1 to 2 minutes).
Add eggs; continue beating until well mixed (1 to 2 minutes). Add light sour cream, grated orange peel and orange extract. Continue beating; scraping bowl often, until creamy (about 1 minute).
Add flour, baking powder, salt and baking soda. Continue beating, scraping bowl often until just mixed (about 1 minute). Do not over mix. By hand, stir chocolate chips and chopped pistachios.
Spoon batter into a greased 9" x 5" x 3" loaf pan. Bake for 60 to 70 minutes or until wooden pick inserted in center comes out clean. (If browning too quickly, cover loaf with aluminum foil.)
Cool 10 minutes; invert onto cooling rack. Cool completely. Stir glaze ingredients together until smooth; drizzle over bread.
**Note: For a more tender crust, do not glaze immediately. Wrap loaf in plastic wrap; refrigerate overnight; then prepare glaze and drizzle over bread.