Debian 8 "Jessie" was released on 25 Apr. A link to the Debian release page shows the changes and you can follow the release in 'real-time' should you desire to do so.
This release will be supported for 5 years and includes "improvements" to the UEFI software (both 32- and 64-bit) introduced in the previous version, "Wheezy". It also is the first release to use systemd as default init system replacing the earlier sysvinit, which is still available in the repos should you wish to revert the change. What effects such a change might have on the remainder of the system is not clear. Improvements to the support of Debian software include the ability to browse and search all source code distributed in the latest release.
(Score: 1, Informative) by Anonymous Coward on Monday April 27 2015, @02:17AM
Uh, no, you just install a different init package.
sudo apt-get install sysvinit-core
Will install the old init system instead of SystemD.
Debian didn't eliminate the old init system, it's just not recommended. If you really desperately want to avoid installing any packages with the string "systemd" in the name, you can use this solution [debian.org].