Yes, it seems to me that small steps of progress are good, as long as some progress is being made. I am watching this thread closely to see where she behaves well, and where she behaves poorly. The sucky thing about NRE is it can make her value her marriage less, and take riskier chances with it. So divorce is certainly a possibility here. My only hope is that some of this NRE will eventually generate some RRE -- Renewed Relationship Energy -- where her new relationship inspires her to renew her relationship with you. We can only hope.
Please keep us posted on how things are going.
Love means never having to say, "Put down that meat cleaver!"