According to an email alert from TSO, ITIL 2011 will be released on July 31, 2011.
This is an update to ITIL V3. Because the basic principles of ITIL are intact, the candidates who hold existing ITIL certification will not need to become re-certified.
As per the ITIL Official Site ITIL Version 1 and Version 2 qualifications will remain valid indefinitely and will still be recognized within the IT Service Management Industry.
Earlier ITIL certifications also hold a credit value under the V3 scheme and can be used towards higher levels of ITIL Certification.