I think there are a few aspects to this. One point is that medal count does mean something in and of itself. When people attempt to assess these Olympic games historically, Michael Phelps will be undeniably the biggest story and the most tangible example of success. It is true that it would be impossible in most Olympic sports for even the most dominant athlete to take home more than a few medals, but that is kind of the point at hand.
As far as how tough his actual accomplishment was, the first thing I think must be considered is just how many world class races he had to participate in over a period of several days. Nevermind the fact that he win every final, but just doing them all had to take a toll. He had to go all out in 8 races at the highest level, plus qualifying heats for 5 of them, over about a week. The guys he was up against did not have to spend nearly that amount of time in the pool. Given that elite racers who specialize in one event still ease through their preliminaries to conserve energy for the final, it would seem that Phelps had put himself at a significant disadvantage in races like the 100 fly simply by all of the work load he had carried to that point in the week.
Phelps's schedule would not allow the possibility of even thinking about the 400m freestyle. Let's consider this for a minute. He is absolutely dominate in the 400 IM and even more so in the 200m freestyle. Is there any doubt at all that he could smash the world record in the 400m freestyle, if he only had the time to try it? I can picture a Janet Evans type of world record that might last until Speedo makes transparent wetsuits with self-flapping arms. The 100m free would be a much tougher challenge, but we've seen how he finishes 100m relay legs and how he came back to win the 100m fly... I surely would not bet against him if he were in a world championship or Olympic medal race of 100m free to pull out the win. It seems as though his dominance is limited only by the number of hours available during a swim meet.
I think the 400 IM wins really set Phelps apart as the greatest swimmer of all time. He would be the greatest without any IM races, but those really make it a closed case. It establishes both his competence in all 4 disciplines and the ability to swim a middle distance race at the highest level. That is pretty amazing stuff. There is no 400m event in Mark Spitz's Olympic medal portfolio. And to go a bit off topic, Carl Lewis and Jesse Owens never ran or hurdled 400m for Olympic medals, and Michael Johnson never ran 100m for one. And remember, this is 2 Olympics in a row that he has won gold in both the 100m fly and the 400m IM.
Edit: Ian Thorpe had the ability to compete at 100m through 800m at a world class level, which is insane. But it was all freestyle, while Phelps has butterfly + freestyle + good enough at the others to win the medleys.
Phelps is 23. Hmm, only 18 years younger than Dara Torres. It's hard to imagine that he wouldn't get at least 4 medals in 2012 with some help from his relay teammates, which would give him 20+ for his career.
It's really impossible to compare achievements in different sports. What Bolt is doing in these Olympics is just unbelievable (although I find it appalling for a sprinter to pull up during a final like that... this isn't the X games)! From the perspective of an American, I can point to U.S. softball or to the beach volleyball combo of May/Walsh, or the women's basketball team.. these are groups that gone for years without ever losing a game. I watched the basketball team with Lisa Leslie and Katie Smith play the Australians in 1996 when the games were in Atlanta. They won that game and every Olympic game since, and those girls are in the starting lineup this year. But the most they can win is one medal every four years. And as I said in the beginning, the medal counts do have a significance in their own right.
As far as how tough his actual accomplishment was, the first thing I think must be considered is just how many world class races he had to participate in over a period of several days. Nevermind the fact that he win every final, but just doing them all had to take a toll. He had to go all out in 8 races at the highest level, plus qualifying heats for 5 of them, over about a week. The guys he was up against did not have to spend nearly that amount of time in the pool. Given that elite racers who specialize in one event still ease through their preliminaries to conserve energy for the final, it would seem that Phelps had put himself at a significant disadvantage in races like the 100 fly simply by all of the work load he had carried to that point in the week.
Phelps's schedule would not allow the possibility of even thinking about the 400m freestyle. Let's consider this for a minute. He is absolutely dominate in the 400 IM and even more so in the 200m freestyle. Is there any doubt at all that he could smash the world record in the 400m freestyle, if he only had the time to try it? I can picture a Janet Evans type of world record that might last until Speedo makes transparent wetsuits with self-flapping arms. The 100m free would be a much tougher challenge, but we've seen how he finishes 100m relay legs and how he came back to win the 100m fly... I surely would not bet against him if he were in a world championship or Olympic medal race of 100m free to pull out the win. It seems as though his dominance is limited only by the number of hours available during a swim meet.
I think the 400 IM wins really set Phelps apart as the greatest swimmer of all time. He would be the greatest without any IM races, but those really make it a closed case. It establishes both his competence in all 4 disciplines and the ability to swim a middle distance race at the highest level. That is pretty amazing stuff. There is no 400m event in Mark Spitz's Olympic medal portfolio. And to go a bit off topic, Carl Lewis and Jesse Owens never ran or hurdled 400m for Olympic medals, and Michael Johnson never ran 100m for one. And remember, this is 2 Olympics in a row that he has won gold in both the 100m fly and the 400m IM.
Edit: Ian Thorpe had the ability to compete at 100m through 800m at a world class level, which is insane. But it was all freestyle, while Phelps has butterfly + freestyle + good enough at the others to win the medleys.
Phelps is 23. Hmm, only 18 years younger than Dara Torres. It's hard to imagine that he wouldn't get at least 4 medals in 2012 with some help from his relay teammates, which would give him 20+ for his career.
It's really impossible to compare achievements in different sports. What Bolt is doing in these Olympics is just unbelievable (although I find it appalling for a sprinter to pull up during a final like that... this isn't the X games)! From the perspective of an American, I can point to U.S. softball or to the beach volleyball combo of May/Walsh, or the women's basketball team.. these are groups that gone for years without ever losing a game. I watched the basketball team with Lisa Leslie and Katie Smith play the Australians in 1996 when the games were in Atlanta. They won that game and every Olympic game since, and those girls are in the starting lineup this year. But the most they can win is one medal every four years. And as I said in the beginning, the medal counts do have a significance in their own right.