Thank you for the replies.
I fall in love quite easily. If things were to work out as I hope, I am going to love her. Maybe not on the same level as my wife, but I am quite certian I will develop feelings for her. But in my twisted mind I don't feel like that will make letting her go devistating.
I have got several close female friends. None a potential match for my situation, but they are near to my heart and I love them both in the sense that I truly care about them, would do anything to help them, have always been there for them when they needed to vent or a shoulder to cry on, etc. One has been in a serious relationship for the past year, so I have had to take some giant steps back. I still love her. I could never tell her becasue she wouldn't understand, but I do. I am not jealous. I realize I cannot be what she wants, so I am happy she found a man that makes her happy.
I sort of think I would be able to react the same if a girlfriend came into my life. All the things I have wished I could share with my non-poly friend, could become real with her, and when the time came she wanted to move on, I think in my heart I could be happy for her and greatful for her giving me the oppertunity to truly know her, to enjoy her sexually and spend time with her.
I know things can go bad and get messy, but there seems almost less chance of that when everyone is upfront with their expectations of how things will be. It seems like in this situation everyone involved should have thought it all out and know what they want as far as long term/short term, are they going to still date other, etc.