The new flat mail address standards proposed have to do with preparation for the USPS new FSS machines (Flat Sequencing Sorters). Mailers need to keep on top of the changes that are coming due to FSS implementation.
There is a good article in DM News
And there is a PCC Workshop in a Box power point presentation on the USPS Postal Customer Council page here
Any questions about what FSS implementation might mean to you, drop me a note.