I think it is here to stay. Coca Cola was the first Real Energy Drink. If you look at its historical advertising it is plain to see that Coca-Cola was supposed to "pick you up". Of course like all things it will change as much as it will stay the same. Peoples taste, attitudes, needs/wants, change constantly and energy drinks are the point that they will change with them. Look at all the derivatives out there: Energy drinks with Juice, with cola,with alcohol, etc. Size differences also. Those things show that Energy drink makers are responding to different needs and wants of it's demographics.
Innovation along with an eye towards consumer demand will always keep energy drink sales climbing.
Whether you think can or think you can\'t, you\'re probably right!