There are four "pure" sprinting events, 60m (indoor only), 100m (outdoor only), 200m, 400m.
On TV, you just see a person effortlessly "sprinting." However, the sprints are actually very technical events. What you don't see is that each race is comprised of four phases: beginning with an explosive start out of the blocks, a drive phase, a transition phase, and finally a sprint phase.
The drive phase - which some commenters have concluded as Pistorius' weakness - is where the athlete builds speed. It is characterized by a forward lean in the athlete and powerful, "pulling" strides. At the elite level, an athlete will remain in this phase for 30m-40m, depending on the length of the race and the height of the athlete.
As the athlete builds speed, it becomes much harder to stay in this forward-leaning position - their legs simply cannot keep up with their body. Thus, they begin to transition into a different style of running. This is called the transition phase - where the sprinter's body moves to from this leaning drive phase into the tall and upright sprinting phase. This can be anywhere from 10-30m.
The drive and transition are important. Some time during these two phases, the athlete will reach their maximum instantaneous speed. At no point after reaching maximum speed will the athlete ever reach that speed again. Thus, the race becomes "who can slow down the least."
The upright sprinting phase is where the athlete tries to maintain the speed they built up during the drive phase until the end of the race. An athlete will be upright, with the slightest of forward leans. Their legs are firing straight up and down very quickly, trying to minimize the time spent on the ground. The ability to do this correctly very much depends on an athlete's "sprint endurance" - which is a completely different kind of endurance than, say, running a mile.
So, on average, 90% of a 60m race is spent gaining speed, 50% of 100m race, 25% of a 200m race, and 12% of a 400m race. The race a sprinter chooses to run depends on whether they are powerful and explosive (shorter races) or how little speed they can lose while upright (longer races).
Here are two fun facts now that you know this information:
1. Marion Jones (who is a cheater) did not have the fastest top end speed out of her contemporaries. She did, however, have the best ability to maintain speed. She was a 100m Olympic Gold Medalist.
2. The Olympic-level weight lifters will outperform Olympic-level sprinters in the first 30m of a race.
There are some nuances to what what I've said that I won't bore you with (for example, some 200m runners can perform a mini-drive on the curve to grab a bit more speed for the straight), but the basic idea is that your sprint endurance is crucial in EVERY sprint race except the 60m. You can make your own conclusions about whether or not Pistorius is legit, but having run the 400m at a high level for a number of years, I can tell you that not being able to feel your calves or feet or have to use the energy required to make them move would have been something I'd be interested in.
I know of at least two athletes for each injury who have either missed training time, an entire season or a career. Injuries are incredibly common in track and field: and make no mistake, there is no emotional-movie-style strength that allows an athlete to overcome their injury due to sheer force of will. Track and field is an 100% sport: if you aren't at 100%, you aren't going to win. A lot of the sport is managing and preventing injury, especially at the elite level.
While I would reason that "upper leg" injuries like hamstring, glute, hip and quad pulls are more damning and common than "lower leg" injuries (especially among men), and that upper body injuries like arms and abdomen are nearly unheard of, being able to write off an entire class of injuries is a huge bonus.
I also didn't mention strength over time benefits: the ability to have a consistent power output of a critical part of your stride (the toe push) that is unaffected by fatigue is very helpful.