I think that having a checkbox for users to sign up for specific mailing lists is a good idea in many use cases. And for that reason, I don't have a problem with there being a general block for all specified mailing lists. However, I only have one mailing list that my users may sign up for, so having the check box there doesn't make much sense for me. I'd like to be able to create a block on a per mailing list basis that will only have text boxes for their email, (and storing their name would be nice too).

Also, rather than hiding the block if the person is subscribed, there should be an option to alter the block to be an unsubscribe block.