I’ve just said this in another post but I really love this plugin, so first thanks a lot for all your good work.
This would be fantastic, as our WP registration process uses double opt-in and activation, so we know that our WP users list is clean and useable.
It would also be great to be able to segment the user list using site roles(for example, we use s2member so it would be nice to be able to target users at a specific membership level, which is achieved using specific site roles like s2member Level1 instead of simple subscriber (which is level 0 / free).
One further extension would be to be able to add a custom field in the user profile for list segmentation. For example, each user has a custom capability field which gives specific access to some of the content. It would also be great to use such field to segment lists further.
If you were able to do this, we would be able to entirely skip Mailchimp for small lists.
Thanks for all your great work!