It was a significant achievement when Bolt beat Michael Johnson's record of 19.32 in Beijing last year. And before Bolt, Johnson's time was so fast that no one else had come even close to breaking it. Now Bolt has done it twice (Tyson Gay ran a 19.58 in May, which makes him only the third runner to break 19.60).
Here is Ethan Siegel modeling 100-Meter world records (for men) over the coming decades based on current rates of improvement, and demonstrating how much of an outlier Bolt really is:
[Y]ou can also see that Usain Bolt is running much faster than humans ought to be running right now. This should give you an inkling of just how special these performances we're seeing from him are. We shouldn't be seeing times like this until the 2030s. Which means, honestly, that it ought to take around 30 years for someone else to come along and break his record.Bolt is only 22, but I think it is safe to say that he is one of the greatest athletes of all time.