I'm not sure of the all the details related to Atomic, but my understanding is that you're correct in its smaller marketshare. Unlike Container Linux, I personally don't know how much time we're going to continue to maintain the distribution. I know there is public information somewhere; I'm going to fire off an email to get more information so that I can clarify this post.
Going forward RHEL and Red Hat CoreOS are going to be the official distributions supported for running OpenShift. RHEL will be for users that need to install software on the hosts themselves manually and CoreOS will be the preferred immutable host that expects all software running at the cluster-level. Running OpenShift on Container Linux or Atomic will be like running RHEL RPMs on CentOS -- it'll pretty much work fine, but I don't think you can call up Red Hat if you get into trouble.
rpm-ostree is super cool. The engineers working on the OS are still trying to figure out how to bring everything together, but we understand how important this technology is. I know this is the hill where the Atomic engineers will die on, so if there's going to be anything from Atomic in CoreOS, it's going to be this, haha.
Going forward RHEL and Red Hat CoreOS are going to be the official distributions supported for running OpenShift. RHEL will be for users that need to install software on the hosts themselves manually and CoreOS will be the preferred immutable host that expects all software running at the cluster-level. Running OpenShift on Container Linux or Atomic will be like running RHEL RPMs on CentOS -- it'll pretty much work fine, but I don't think you can call up Red Hat if you get into trouble.
rpm-ostree is super cool. The engineers working on the OS are still trying to figure out how to bring everything together, but we understand how important this technology is. I know this is the hill where the Atomic engineers will die on, so if there's going to be anything from Atomic in CoreOS, it's going to be this, haha.