As part of the preparation for CentOS 7, and with a growing focus around making the source easier to work with for developers and Special Interest Groups, the CentOS Project is publishing the git source tree used for building the distribution. This represents a bit of a change from previous releases and we understand that it will cause some users to change their workflows a bit. We've put together a wiki page outlining how to get the sources, and a brief walk-through for using the tools to make it easier.
If you're interested in working with the code for various SIGs, to help us with branding hunts, or just want to play around with the source for your own means, please see http://wiki.centos.org/Sources. If you have questions or would like to make improvements to the toolkit, please join us on the centos-devel mailing list at http://lists.centos.org/mailman/listinfo/centos-devel.