The 4.0 still have 2 public sprints and a few private tasks I dowt they would get that all done in less than 25 days (plus weekends they are closed), the mass mailer only works on 4.0 as it needs changes to the core so that answers your next question. Why not do it the way people do it now? Use the report feature (Billing > Reports > Custom reports) and then use that XML for Mailchimp etc.
SELECT contacts.client_id, contacts.first_name, contacts.last_name, contacts.email, contacts.address1, contacts.city, contacts.zip, contacts.country
FROM contacts
ORDER BY contacts.client_id;