Wow, much has happened since we gave users a sneak peak at OpenFlight API 5.0 at the I/ITSEC OpenFlight User Group Meeting in December 2011. At that time (as you noted), we originally penciled in this new release for Fall 2012. We've delayed the release and have made adjustments to the release target date at subsequent User Group Meetings (minutes for those meetings are posted at http://www.presagis.com/standards_forum/viewforum/28/).
In any event, we are busy finalizing the OpenFlight API 5.0 release currently and hope to have it out in the next few weeks.
Stay tuned on these forums for further announcements.
Has the Open Flight API v5 been released yet?
It was scheduled for Fall 2012.