This post is a few weeks old by now, but I thought I'd cross-post it anyway. Mark and I worked on the post after having a brief discussion about a few customers who were hesitant to remove the old ADMs. Check it out: http://blogs.technet.com/b/askpfeplat/archive/2011/12/12/how-to-implement-the-central-store-for-group-policy-admin-templates-completely-hint-remove-those-adm-files.aspx