Personally it won't really affect me. I very rarely receive a letter or anything in the mail that is very vital and timely. All I receive in the mail are bills that are due a few weeks later, and half the time I receive/automatically pay them online. As for pay checks and stuff of that nature I have everything that is direct deposited.
Other important documents I would just have fed ex or UPS overnight it if it's that important.
Honestly, I think they should only deliver 3 days a week, Monday, Wednesday and Friday. It would help USPS cut expenses by a lot, unfortunately though it would take a lot of jobs away. The only thing that I think USPS should do before that, I am sure there are tons of employees that are unnecessary, I'm sure their organizational chart is all screwy and they should probably optimize that first.