I surely hope not.  Marketers must be able to reach their prospects via email, at least at this point in technology.  And, while RSS can deliver many things, email is still a relevant means of communication.
However, email marketing is almost broken. 
Trigger-Happy Consumers. When a senator counts how many people
in his district have complained about [...]

While RSS is a great tool for marketing, email will always be necessary as well.  For opt-in marketing, the delivery method is great, but because of spam concerns many feel a change must be made to avoid destroying the medium altogether.
Skylist is one company that is working to create a whitelist of email domains, and [...]