"ISACA has tapped its global network of leading IT governance, control, security, and assurance experts to develop a widely embraced framework to help ensure the quality, consistency, and reliability of IT assessments. ITAF also contains a helpful set of good practice-setting guidelines and procedures."
The ITAF content is largely a repackaging of existing ISACA standards and guidelines in the areas of IT audit, assurance and governance. I'm pleased also to note that the ISO27k standards merit a mention.
ITAF is free to ISACA members, $45 for infidels.