As mentioned in my last, SAS70 has offically retired. SSAE16 (Statements on Standards for Attestation Engagement No. 16) has taken its place and improves upon SAS70 in several ways.
The improvements come from a shift of focus. SAS70 was about ensuring your control framework was sufficient and functional. SSAE16 is about ensuring your systems -- including deployment and controls -- are sufficient and functional. SAS70 was focused on the control structure around specific threats. SSAE16 incorporates risk management and ties together risks, threats, and controls. Going into this, SSAE16 looks set to provide a more complete result.
Another improvement is in the shift from audit to attestation. SOX (Sarbanes-Oxley Act of 2002) requires executive management to attest in writing to the accuracy of the financial statements. comparison, SAS70 does not require attestation. SSAE16 supports SOX by requiring a written attestation of the audit's accuracy from executive management.
SSAE16 should provide a holistic audit with greater executive management participation. This is the first year I have done one, and my audit period begins in a couple months. Wish me luck!