I actually just built a whole newsletter system, just finished it a few days ago.
It is set-up much like powercms.
wysiwyg editor,
allows for images and sets the whole path to images dynamically so you don't have to,
set subject lines for the email,
change background color of the newsletter,
control amount of blasts to stay in good graces with your web host,
subscription page
newsletter has opt out link built in,
subscriber database control center...so you can easily add/remove emails manually
all the help files are already...ready to go
I was actually considering contacting WA to see if they were interested in this.
vanroojdotcom, email me at gruant2000 (at) yahoo (dot) com if you want a copy of it.
WA, you can email me also if you are interested in this product
(I have a working demo up and can give you the log in info to test it out)