South African Pistrious won triple gold in 100m, 200m and 400m in Beijing but acknowledges he won't have it all his own way in London, especially over the blue-riband shortest distance.
Peacock, just 19, smashed the T44 class world record in Indianapolis earlier this year while USA's Jerome Singleton won the world title in Christchurch in 2011.
“In May when Jonnie ran 11.4 for a personal best, I was asked what I thought about him," said Pistorius, who is again expected to be one of the faces of the Games.
“I said, ‘Well, he’s a youngster, he’s coming up through the sport and he’s still got a lot to learn’.
“Then he went and broke the single-amputee world record and improved by more than half a second; you never see that, especially in the 100m.
“I’ve been more than impressed and I've had to eat my words."
Pistorius insists the 100m is his 'fun event' with his main aims for the Games over 200m and 400m, in which he reached the Olympic semi-final earlier this month.
And he believes Singleton's experience could trump Peacock's raw potential.
“Jonnie is a huge threat. My personal opinion, though, is that experience counts a lot,” added Pistorius.
“Jerome Singleton is a true professional, a very serious guy who doesn’t let competition get the better of him.
“He’s going to be just as much of a challenge. He’s been one of the only athletes to beat me in six years in the 100 and he’s definitely a guy who stands up when it matters.
“It’s important to note that I haven’t run a 100m personal best in five years. It’s not really my event.
“As Jonnie and those guys focus on the 100, my focus is on the 400, on the complete opposite side of the spectrum when it comes to sprinting.
“I like to see the evolution of the event happening and if that means I’m not at the top of the event but the sport’s getting quicker, that’s OK with me."