In that case ... Does anyone have an E.T.A. on 6.2.2 ?
I would really like to have this features as quickly as possible. It will be a great way to create additional marketing channels. You could "sell" the rights for a sponsor to one specific area (new registration, lost password, private message notification, topic reply notification, etc)
The idea of tracking everything and controlling it within the cp.cgi is what will make it that much more robust.