Not true -- people will remember Steve Jobs for his Pixar films. I also suspect that Bill Gates may be remembered more for his philanthropic work than his tech work if he can pull off something big. As for tech we still associate Edison with film and records, so Jobs and Gates may still have a shot at it.
While I enjoyed some of Gladwell's writing, this is bullshit. If you don't think that copying happens everywhere, you should watch everythingisaremix.info. Jobs took pieces of a million things and put them together in a way that made the most sense and connected culturally. Jobs won't be forgotten for a long, long time, just as Thomas Edison hasn't been forgotten. Gladwell's flat wrong on this.