Thanks for implementing subscribers for Phame blogs! Still trying it out, but I feel that we now have an actual shot at using it for internal communications.
So, regarding comments: Ideally I wouldn't have to tell people to change the comments setting to enable (Facebook/Disqus) comments, instead I'd be setting the default somewhere and people can just post without changing any settings.
To me, this seems like it could be a per-blog setting. Globally would also work for me though.