Why does everyone want to get rid of Saturday delivery? Why not keep Saturday delivery and eliminate OTHER days? If we're going to scale back, at least keep a day that is useful for most people. A lot of packages that ship via USPS require signature confirmation. By keeping Saturday delivery, you make it easier for people to get packages without having to go to work late or leave work early (during post office hours). In addition, a lot of people have no way of getting to the post office (think the elderly or people without cars), so Saturday delivery is useful.
Keep Saturday delivery, get rid of a few other days. All of the postal employees are union anyway, so why not?