Just going to sum up all my replies to the above posts in one to save me the time, so here goes.
Firstly, it has been stated that the "Derma" ball is in fact a deformity.
Now in my opinion a "deformity" is something that is detrimental to the success of an animal (success in evolutionary terms means reaching breeding age and producing offspring). In order to determine this we must also take into account the habitat the animal is striving to survive within.
Now lets apply this to the case of the "Derma" ball. This animal is kept in captivity, so reaching breeding size should be dependent on the health of the animal, ability to eat well, etc. Now if this animal was in the wild, it would be arguable that the lack of scales or heat pit scales (note, we do not know if this animal cannot receive heat sensory till there is a test done to prove it either way) would be detrimental to the animal most likely leading to death. The same case though could be made of an albino animal, an ivory, super mojave, pied, etc. (lack of black pigment makes thermoregulation tougher for the animal, lack of camoflage, etc.)
The problem with all of the "detrimental" and "deformity" talk is that this animal resides in captivity. Its' success is dependent on reaching a large enough size to breed and produce progeny. Sure the animal may require better humidity control due to its' lack of scales, but this requires slightly different animal husbandry, and would not inherently be detrimental to the animal except possibly in the wild (who is to say a scaleless animal wouldn't adopt a different niche due to its' peculiarity?)
So in summary, I think everyone is arguing over the wrong things. The true point to argue here is whether or not this animal's quality of life is impaired by this mutation.
Also just wanted to point out that this isn't some freak of nature folks, this is just another shining example of the genetic variation within the ball python population, it is evolution, and if this mutation within captivity is selectively bred for, then it is a successful mutation within the habitat within which it resides, that is all.
Dan