Originally Posted by Shell

...i used to be a Graphic Designer/illustrator. Logos were my specialty and even I didn't see that arrow in the FedEx logo right away. The goal of a Graphic Designer is Visual Communications. If many are not getting it then the logo design really wasn't successful. To lightly shade in the arrow makes it happen...they really ought to change it to that.

...the concept is clever enough that they really shouldn't lose it in the negative space that most people don't see.