The CentOS Project is pleased to announce the immediate availability of CentOS 7 for x86_64, including images for docker, and various cloud providers. There are many fundamental changes in this release, compared to previous releases of CentOS. Notably the inclusion of systemd, Gnome3, and a default filesystem of XFS. For more information about what makes CentOS 7 stand out, please see their release notes.
You can perform an upgrade to CentOS 7 from 6 release, however there are certain functionality to be ironed out.