I don't believe in waiting til the marriage is over necessarily as it can take so long. In which case, a lot of us here should not be dating etc. I do believe if your properly seperated and both parties have accepted that (even if one is still clinging but it's been a long time) that it's fine to move on.
I say do what you want..to each his own..all I say is don't be an OM and if you interject yourself in before she is done then there becomes a chance you will be a shoulder for her to cry on and something could develope. I think if we search back through my threads then we might see where you gave me the same advice for cafegirl34?? I removed myself from that sitch before anything started...and she is still with her "live in" boyfriend..