Newsletter Conditions for Rules

Could we have conditions for the Rules module that test against whether an e-mail address is signed up for a newsletter?

Test case:
I created my own field check box to sign up for a newsletter, as I didn't like how the default one was formatted. I used rules to tie the check box to a user's subscription when they registered or updated their account. At some point during various tests, I generated a case where I tried to unsubscribe a user that wasn't subscribed, and that resulted in an e-mail being sent to them about the incident. I'd like to update my Rules unsubscribe logic with a condition that checks to ensure they are in fact subscribed, and my subscribe rule to make sure they aren't already subscribed.