It is now possible to export configuration files for a project with its children as a zip archive to move it to a different TeamCity server. The Project Settings | Settings Export page allows exporting the config files for a project and its subprojects, as well as external dependencies, i.e. build configurations used in snapshot dependencies, templates used as well as vcs roots and all main settings (ssh keys, issue trackers, oauth connections etc...) defined in the parent project.
The settings archive also contains a report.log file detailing the reasons for exporting external entities.
The Commit status publisher build feature now supports GitLab thanks to an external contribution.
If you use Perforce jobs to label your commits, the changes associated with jobs are now marked with a "wrench" icon 
in the TeamCity UI. Navigating to the icon opens a pop-up with the job information:
In this EAP projects and build configurations as well as collapse/expand actions received new icons. Overall, the UI boasts of a refreshed look and feel.
It is now possible to run a custom script on the launch of an Amazon EC2 instance (applicable to instances cloned from AMI's only). The Amazon website details the script format for Linux and Windows.
TeamCity comes with built-in support for many of issue trackers, which now include Bitbucket. The integration with Bitbucket issue tracker can be set up separately, or as a part of TeamCity integration with Bitbucket source code hosting service making it easy to connect TeamCity to Bitbucket issues.
you can now redefine inherited artifact dependencies in build configurations, the same as agent requirements and other settings