According to TIME, This American Life has discovered Coke's secret formula. Here it is:

The recipe:
Fluid extract of Coca: 3 drams USP
Citric acid: 3 oz
Caffeine: 1 oz
Sugar: 30 (unclear quantity)
Water: 2.5 gal
Lime juice: 2 pints, 1 quart
Vanilla: 1 oz
Caramel: 1.5 oz or more for color

The secret 7X flavor (use 2 oz of flavor to 5 gals syrup):
Alcohol: 8 oz
Orange oil: 20 drops
Lemon oil: 30 drops
Nutmeg oil: 10 drops
Coriander: 5 drops
Neroli: 10 drops
Cinnamon: 10 drops

This seems too...natural...to me. I just assumed they made Coca-Cola out of a proprietary blend of high fructose corn syrup and molten plastic these days.