Did you get our Useful WPMU Links newsletter?
If so, why don’t you go send some of your own with the WordPress MU MailChimp integration plugin!
It really is da bomb – allowing WordPress MU users (or single WordPress.org users) to simply (and I mean *really* simply) import all of your registered users into MailChimp and then have new registered users added too.
All you need to do is upload it, sign in, select your options and you’re away… shiny, happy email newsletter goodness will be yours!
Check out the options page: