While currently K-rod or Francisco Rodriguez may be dominating the sport of baseball with his eclectric stuff as the closer of the Angels, there is a major problem that concerns me. He like the majority of pitchers in MLB have piss poor mechanics. To generate the arm speed most pitchers just throw with their arms and not their lower half where the torque should come from. K-rod is a prime example of this. He flails around with his herky jerky motion and falls off the mound to the side. All the flailing and crazy herky jerky movements puts an extreme amount of stress on his shoulder and his elbow.
The big idea here is that even with proper mechanics the human body is still being pushed to its limits of breaking down. So if you factor into that a pitcher without proper mechanics then you will most certainly have an injury prone pitcher like Mark Prior. Sure he has electric stuff out on the mound. That is, when he is out on the mound and not sitting on the bench while on the DL again.
Take a look at the five foot ten inches tall pitcher for the San Francisco Giants by the name of Tim Lincecum. He throws his fastball 98 mph. You might ask how he does it, and the answer is perfect mechanics. He moves his body such perfect harmony that it allows him to generate the max amount of torque with his hips, thus producing the max velocity on his fastball. K-Rod on the other hand is Herky Jerky McGee.
When K-rod broke into baseball in 2002 he threw the ball in the mid to high 90's. Now his velocity is around 92 mph. That is a concern considering he has not been pitching for that long. I do not see him lasting very much longer without having a serious problem with shoulder or elbow injuries. With him heading into free agency many GM's would love to spend the cash to grab an arm like that. But with the highly likely injuries that come with bad mechanics, I would look at the situation very cautiously.