The russians behind ROSA Labs (the same people who build ROSA Linux) have come up with a testing rebuild of RHEL, "imaginatively" called RELS, "ROSA Enterprise Linux Server".
There are rumours the "Russian Fedora" community is also involved.
I hope this clone will move out of testing and into proper production. I'm so bored with Centos and ScientificLinux. :-)
More info here:
http://www.rosalab.com/blogs/test-edition-of-rosa-enterprise-linux-se
PS: Got in touch with them and they specified:
We've already done some additions: 1) we've ported Mandriva Directory Server, Mandriva Setup Server and Mandriva Management Console to RHEL6 basis; 2) we provide pretty minimal LXDE Desktop (we're the first who build LXDE for RHEL6-compatible distributions); All our additions come to "extra" repository, while "base" mainly consists of RHEL6 packages to provide 100% binary compatibility.