The Postal Service has released an industry survey regarding a reduction of mail delivery to five days:

Despite very aggressive cost cutting, the Postal Service is projecting financial losses for this and the next several years. This is due to a significant decline in mail volume and a major requirement to prefund its retirees health benefits. The Postal Service is committed to fulfilling its fundamental role as a deliverer of mail and packages to all Americans. To accomplish this, the Postal Service is developing a plan to transition from six- to five-day delivery on a national basis. This will remove delivery costs and help bring the financial picture into better balance. The alternative would be large price increases.

The survey is available here and takes about 5 minutes to complete.

The Postal Service is considering no delivery or mail collection to homes and businesses on Saturday, while maintaing PO Box delivery, and delivery of Express Mail on Saturday and Sunday.