I've posted a first build of CentOS for the Hikey from 96boards, and a ReadMe with the steps required to get the board going.
http://people.centos.org/jperrin/hikey/
The ReadMe assumes that you've at least skimmed the 'Getting Started' section of the Hikey documentation, but walks through the fastboot commands to load the image.
What I consider the 'blocker' to releasing this image presently is the lack of console output on HDMI. If someone's able to make that go, I will happily mail them some CentOS swag and put their name in the release notes for the image.