Ok, -everyone- knows it, this new version introduces a number of interesting updates, one above all: openssl version 1.0.1.
Openssl is the library used by many programs to perform encryption tasks, for example it’s used by openssh, webservers, etc etc.
The version included in CentOS 6.4 was really outdated, it doesn’t support TLS v1.2 for example, so I had to install it separately (which is a PITA to say the least).
With the new version included in CentOS 6.5 TLS v1.2 works out of the box, keep up the good work CentOS team.