Thank you all. Her and I are going to have lunch on Monday, and I've asked her to bring me all my stuff. I lived there part time really so it's not just a couple trinkets. I think this might make what she's decided more real for her. There have been times when i've take stuff for one reason or the other and it always freaked her out and lead to "are you breaking up with me?" questions. So I don't know if that's relevant at all, but at least in my messed up mind i'll maybe get to see her hurt as much as I am.
As far as what will happen when/if the relationship she's starting fails, I don't know. I've been wrestling with this myself. I want to tell her in no uncertain terms that if/when it does, her and I will continue to be what she's decided we're going to be now, not what we were before. Problem is of course, I don't really feel that way and would probably take her back in a heartbeat. The problem I see with that is I'm left basically as a safety net. It lets her not have to worry about things, or worry about what's going to happen if it fails because she know good 'ol bill will be there for her to pick up the pieces.
Thanks again everyone, a little bit of validation can go a long way. I know as poly I'm not supposed to be jealous and I'm supposed to be hurt when I help someone get better and they move on.