Of course not. Most likely, nobody else ever will again.
The last person that repeated was Johnny Chan in 1988. That's when there were still only 167 people in the Main Event!
When Moneymaker won, there were still "only" 839 entrants. When folks saw that a complete nobody could actually win the Main Event, the poker boom really took off. The very next year, 2,576 people entered the main event. Then 5,619, then 8,773. Since then, it's leveled off around the high 6 thousands.
Add to that the fact that Moneymaker is a mediocre player, and the answer is "no". He won't ever repeat.
Is there a chance? Well sure. I'd lay 500 to 1 against him ever repeating the rest of his lifetime. I'd lay 10 to 1 against anyone ever repeating again in our lifetime.
WTF are you talking about? I'm looking at every answer, and I don't see that anyone criticized him. I called him a "mediocre player". That's not a criticism. Mediocre means medium. He's not bad, but he's not great. That's not a criticism. Relax. :\