The current version of the standard is version 2.0, released on 26 October 2010. PCI DSS version 2.0 must be adopted by all organisations with payment card data by 1 January 2011, and from 1 January 2012 all assessments must be against version 2.0 of the standard. PCI DSS version 2.0 has two new or evolving requirements out of 132 changes. The remaining changes and enhancements fall under the categories of clarification or additional guidelines.[2] The table below summarizes the differing points from version 1.2 of 1 October 2008[3] and specifies the 12 requirements for compliance, organized into six logically-related groups, which are called “control objectives”.
PCI DSS originally began as five different programs: Visa Card Information Security Program, MasterCard Site Data Protection, American Express Data Security Operating Policy, Discover Information and Compliance, and the JCB Data Security Program. Each company’s intentions were roughly similar: to create an additional level of protection for card issuers by ensuring that merchants meet minimum levels of security when they store, process and transmit cardholder data. The Payment Card Industry Security Standards Council (PCI SSC) was formed, and on 15 December 2004, these companies aligned their individual policies and released the Payment Card Industry Data Security Standard (PCI DSS).
In September 2006, the PCI standard was updated to version 1.1 to provide clarification and minor revisions to version 1.0.
Version 1.2 was released on October 1, 2008.[4] Version 1.1 "sunsetted" on December 31, 2008.[5] v1.2 did not change requirements, only enhanced clarity, improved flexibility, and addressed evolving risks/threats. In August 2009 the PCI SSC announced[6] the move from version 1.2 to version 1.2.1 for the purpose of making minor corrections designed to create more clarity and consistency among the standards and supporting documents.
http://en.wikipedia.org/wiki/Payment_Card_Industry_Data_Security_Standard