CentOS 5.6 for x86 and x86_64 platforms was released on Friday after a number of delays. There's also CentOS 5.6 LiveCDs available.
Release notes for CentOS 5.6 are available here and the release announcement offers up the download links.
There's still no CentOS 6.0 release to provide a community spin of Red Hat Enterprise Linux 6.0 nor any signs of that even coming soon. Fortunately, there is at least Scientific Linux 6.0, which is already out there and serves the same purpose.