And now for the real answer http://www.centos.org/modules/smartfaq/faq.php?faqid=7
We have goals for release ... our goals are:First time release (for example, 3.0, 4.0, 5.0)
: Our target goal is 1 month. This is obviously the longest situation as this is a BRANCH
or version of CentOS that has never been tested and it requires much QA and usability tests, etc. Update set release (for example, 3.9, 4.5, 5.1)
: Our target goal is two weeks. This type of update normally changes 10%-30% of the packages in it's tree and requires more QA than individual releases but less time to test than a whole new tree. Longest time has been one month.Normal security or bugfix updates between update sets
: Our target goal is 72 hours and we normally complete these within 24 hours.
So ... for 5.1 (and the upcoming 4.6) our goal for each is 2 weeks to finish the updates and get an ISO set. Then 2-3 days to get them synced to all the internal mirrors and another 2-3 days to get them to all the external public mirrors. At that point there will be a release announcement.
The realistic date that I would expect the release announcement (if we have no unforeseen problems) would be in the neighborhood of 26-30 November 2007