This is the way I see it. I currently run a company with a very very large install base of machines.
My machines are all running Centos 5.x. For me, getting 5.6 out to production is the HIGHEST priority. I could give a crap about 6.0, especially since everyone knows that the first RHEL x.0 release will be completely buggy anyway. For deploy-able stable products, RHEL 4.3 and RHEL 5.1 were the first in their series to be decent enough to run in production from our testing and bug reports back to Redhat's bugzilla. I completely expect RHEL 6.0 to be completely unstable and bug ridden, and hopefully 6.1 has ironed most of them out.
I'd be perfectly happy if CentOS never released a RHEL x.0 release.
I personally think Scientific Linux has their priorities backward, and CentOS is in the right. I'd rather have 5.6 before 6.0.