If your snake (or whatever) is one of the spiffy new morphs .. there is a fairly good chance that it has been inbred somewhere in its lineage.
Line breeding is a relatively common practice used to prove a genetic trait. If you look at animals like dogs, you can see the results of over-inbreeding. Breeds like the dalmations, german shepards, chows all have inbreeding related problems (hearing problems, hip displacia, eye problems). Wild cheetahs are inbred out of necessity .. there isn't enough genetic diversity left in them! They are all essentially siblings .. well, genetically, they are all pretty much the same animal.
From what I can see, don't worry TOO much about inbreeding, but keep a close eye on the results, and don't continue a line that has problems (please, the hairless cat is gross enough, let's not breed a furred snake.
Just my rambling opinion.