"The ultra-stable enterprise distribution model seems to be in no danger of going away, " It seems that the Red Hat kernel is not stable feature-wise but only in terms of routine functionality. If they can (and I take it they have) make backporting work to the OS's users' benefit I can't see any problem with that. I use CentOS because it gives me good functionality and good stability. If I needed paid-for support there's RedHat. I don't think this is such a big deal.