If you are refering to the protective plastic between the keyboard and screen, it has been determined and verified by Verizon folks (in a diffent thread) that you are safe to pull it off, and it slides easier afterwards.
There is actually a big thread on this. It is in fact suppose to be pulled off. One of the members had a chat session with verizon, and they stated that it's there for shipping purposes and is in fact supposed to be removed. Though you do not have to remove it if you don't want to. Some members stated that it was already peeling away so they removed it. Others said they will remove it only if it becomes a problem.