I'm hardly a "pro". If I was I still wouldn't be here 5 years after my first visit.
But...I think the goal should be to be friends at some point. It may take a long time after a divorce for that to happen. But, especially if you have children together (and some day grandchildren) I think it's imperative to have the absolute best "after marraige" relationship possible.
For me the big issue is being too friendy in the midst of the separation/divorce process and letting my WAW use me as a doormat.
There is a way to have boundaries, self respect and still be friends - unless of course, your spouse, or former spouse is behaving in a way that you wouldn't consider in any friend.
If that friendship allows for reconcilation at some point - great! But, you can't do it just for that faint hope.