Possibly OT but I would gladly pay to use something like mailchimp or aweber lite if the deliverability/reputation was good. Lite in this case meaning 10 minute admin learning curve and a simplified feature set. I know that's vague. but in general I find the the current crop of email web apps to be bloated and hence too time consuming.
Also would be useful for business if I could "private label" the service to work on my own domain name (or sub domain) simply by adding a fiesta.cc mx record to my dns.