Styling:

It would be really helpful to add HTML functionality is the Newsletter Templates area. Not necessarily an HTML tool, but just allow general HTML to be placed in the text area. Example, I want to add a MastHead so that people will always look for my newsletter, and I want to add a couple of columns and advertising banners. Lining up everything on the left and in just plain text is pretty boring (even though their spam filters would be happier). You may also want to give an option of Plain Text or HTML.

Opt-Out:

All newsletters (or mass emailings) should give the ability to opt out at the tail end of the newsletter. While some people become members it doesn't mean they want to receive newsletters. Some standard text at the end of the newsletter might be:

"You have been sent this email because you are an existing member, you or someone within your organization has requested information from our website in the past or has opted-in to one of our affiliate's programs. Click <a href="http://www.domain.com/optout">here</a> to avoid receiving future e-mails from us. You may also write to us at Domain.com, Address, City, State, Zip."

Just a thought.