Sending e-mail notifications to users when their Role is changed

Does anyone know of a plugin or function that would enable you to send users an email notification when their role is changed, much like they receive one when their account is created?

I’d love to tell users what their new role is, why it changed, included a badge, etc…

New User Email Setup seems to allow you to customize the initial registration email, but nothing more = http://wordpress.org/extend/plugins/new-user-email-set-up/