While the aluminum body of the MacBook Air/Pro might be nice to look at, there are some who might not enjoy the touch of cold metal on their palms especially while typing. That and there are those who are hoping to avoid staining or scratching the body of their MacBooks which is why you might see MacBooks with a cover or a palm rest. It sounds like a good idea and you think that this will help in protecting your laptop in the long run, or possibly because you think that the palm rest you chose looks really pretty, but whatever your reason, it seems that Apple is advising users not to do that.
Ubergizmo , Apple advises against using palm rests for your MacBook, Apple advises against using palm rests for your MacBook
