I think they are in today's NBA but certainly not the greatest of all time. There are so many players who have done that to a much higher level than Nash and Amare although they are a very good tandem.
Shaq in his early days was just as if not more athletic than Amare. You can't discount Larry Bird or Kareem. Amare is a good young talent but you can't compare him or his athleticism to the all time greats. Even Dennis Rodman was very athletic when he was in his prime. Can't judge someone too quickly or too early in their careers.