The USPS has published their latest IMB Standards in the Federal Register.

In May 2009, all letters and flats requiring a barcode and mailed as First-Class Mail, Periodicals, Standard Mail, and Bound Printed Matter would be eligible for full-service prices which will be lower than the basic service (and POSTNET) prices.

All references to May 2009'' refer to the date that they implement the May 2009 Mailing Services price changes.  The USPS would provide free automated address correction notices for correctly formatted mailpieces (in a full-service mailing) that have the appropriate ancillary service request (either Address Service Requested or Change Service requested) in their mailer profile and embedded in Intelligent Mail barcodes.

They will have two price points, not three.  POSTNET and Basic will be the same and both less discount than Full-Service. Also, ACS is unlimited.

See the Federal Register. The proposal includes revised mailing standards.  Mailers are encouraged to review and comment by May 30 by writing to the Manager of Mailing Standards, U.S. Postal Service, 475 L'Enfant Plaza SW, Room 3436, Washington DC 20260-3436, or e-mail IMB&EDOC@usps.gov.