Some of the people in my organization have been certified on ITIL V2. Do we all need to go to V3?

No, this will not be necessary as the changes in terminology and to the actual processes are not that great. People should take the training at whatever time is appropriate for them to support their specific needs/ initiative. For those who do take ITIL® V2 training and later want to learn the specific changes made in ITIL® V3, a short update course will be available from The Art of Service education services beginning April 2007.