What goes up must come down and on Wall Street, billions are made and lost betting on which direction companies are headed. Apple is the most valuable technology company in America by a huge margin so needless to say, it gets plenty of attention on the Street. At some point, be it sometime in the next few years or sometime in the next few decades, Apple will no longer be on top. It is inevitable. The question countless industry watchers try to answer, of course, is when. Various guesses — sorry, estimates — have been made in recent years, and the boldest among them have been off by a laughable margin. In mid-2011, for example, Pyramid Research released projections that showed