This plugin is much-needed, and MultiSite support will eventually be very important too. Thank you for this plugin. Here are some error reports:
1) When you click to approve someone, their status changes to approved, but their user account level doesn't change from Unapproved to Subscriber. So the effect is the same - locked out - until you click into the user, change from Unapproved to Subscriber, and save.
2) The Admin gets an email to approve (or not) a new registration, but the new user doesn't receive the emails stating that they need to be approved.
3) No email goes out to the new user once approved (or disapproved I assume, although I didn't test this scenario).