20 years from now they'll probably discover that the current consumption of such high levels of synthetic stimulants will cause brain cancer and your genitals to fall off.
Either that or they're actually good for you. They're called preservatives for a reason. ;)
"Try new Pepsi Pharoah with extra mummifying preservatives!"
Also, there is a new flavor of Coke called Diet Coke Plus flavored with aspartame and acesulfame potassium:
http://en.wikipedia.org/wiki/Diet_Coke_Plus