I agree with xluckythangx, and i am also a girl, about saying she is thinking of moving away. Now this may not be the case with your ex, but it certainly is the sort of thing i would do if i wanted to see how someone felt about me, that i would hint at moving away to try and get them to persuade me not to...its a game i know but...sometimes it works...
Maybe you could just ask her if she is serious about moving out of state and just say you will miss her if she does (in a not overly sentimental way e.g. don't throw yourself down at her feet sobbing as you say it)...by saying you miss her you're not actually saying whether you will miss her as a friend or as someone who is still in love with her....and then gauge her reaction..if you do it this way then you've not kind of made yourself too vulnerable like you would do if you confessed you wanted to get back with her.