Past weekend we installed several Debian patches and were surprised that /etc/debian_version changed to 7.5. Usually there are announcements on the Debian website and mailing lists about that...
date; cat /etc/debian_version
Tue Apr 22 09:22:25 CEST 2014
By digging a little through the recent mailing list mails, I came across this topic with the following content:
Upcoming stable point release (7.5)
The next point release for "wheezy" (7.5) is scheduled for Saturday, April 26th.
Stable NEW will be frozen during the preceding weekend.
See https://lists.debian.org/debian-project/2014/03/msg00158.html for the archived mail.
Seems that 7.5 was (accidentally?) released already a week before the scheduled date.