Thanks for all the comments so far.
NeedsCoffee - we mentioned in the post we have plans for SMTP AUTH - we're working hard on those and will announce more when we're ready.
silverts and JanKetil - same answer as above. Yes, we have plans. Will announce what when we're ready. Work still to be done.
SpartanWaycomau - we agree and while this post is all about October next year we are going to be changing defaults for new customers sooner. We can't easily change something like this for existing customers like you without notice, that's part of our terms of service with you. But we do want new customers secure by default and we are considering turning off Basic for customers we know don't use it. We are also going to be sending tenant admins Message Center posts specific to their own tenant's usage. So look out for that.