advice: default to not bringing things up AT ALL, avoid having the 2 in the same place as much as possible, also avoid talking about the other person AT ALL...do nothing untill you are sure you know the feelings of the person whom you are talking to.
My experience- my parents are divorced, I love them both, it took "them" 10 years and my wedding ceremony to finallly be able to occupy the same **building** together (one parent even intentionally arrived 15 mins late...TO MY WEDDING :mad ...so he/she didnt have to sit next to the other). I'll admit that one parent was more easy-going than the other, but that still prevented me meeting the 2 of them for an event. It *may* take up to a few years...yeah, if things are bad it could take years...for their feelings (about each other, you, your role in the issue...) to get really sorted out- you may need a lot of patience with both/one of them to keep the friendship going...
(I swear, if he/she werent my parent, I would have stopped talking to her/him long ago) I hope that my parents have a 'worst-case divorce" scenerio
...actually
...all divorces are 'worst-case..."
Or, (I hear people can do this, but never seen it =) ), in a year feelings will be solidifed, divorce(/child arrangements ?) will be finalized and you will be well versed in how each party feels. Sometimes it takes a year or more for just the court proceedings/legal stuff to get worked out. I wish you luck. (my parents are stilll arguing child support issues in court...
Lastly, since I was 16 when my parents seperated, I would ask that you do what you can for the children (if they have any)- It royally sucks (first my parents seperated, then 6m later my then-girlfriend's parents divorced, so I've seen it from the inside and the outside). There probably isnt a lot you can do, but if there is (take them to the zoo, offer to talk/listen about whats going on...children suffer greatly in any divorce) helping thier understanding and giving them an 'outside source' for information/compassion will help them out in the long run.
whoa...you seem to have hit a nerve =) , sorry if this post is too long.
This post edited for fairness to my parents =)
-John