Little bit of history on this one, back in the early 80's you'll remember the Pepsi Challenge commercials. This was a hugely successful marketing campaign that was slowly taking a significant amount of Coke's market share after dominating the industry forever. Coke was on downward slide and needed to do something... In attempts to stop this loss of market share Coke decided to dump the original Coke and introduced New Coke which was pretty much a big failure and they continued to lose market share. A very short time later they reintroduced the original formula as "Classic Coke". The rest is history, the marketing campaign for this erased much of the gains Pepsi made and they haven't looked back since. New Coke? I dunno do they make it anymore?
There has been speculation that the reintroduction of Classic Coke was in the plans all along and the very short time span between the introduction of New Coke and the reintroduction of Classic certainty supports that. So the question is was this move pure genius or did they step in it? I will tell you one thing, if it was the plan that is one slick move.