Just the fact that she is receptive enough for me to come over and talk with her is at least a little bit telling. She hasn't completely shut down any communication is a good thing right? So I should cancel and act as though its no big deal and "we will talk when we talk" type of thing?
No, it isn't. You will always be in some form of communication due to your son. Always. Best bet is that she wants to talk about how she thinks the divorce should go. Have seen it so many times on here. In fact, we had a huge discussion about this same thing earlier and the consensus is what I'm saying. She has her terms and agenda. They may/may not agree with yours. Don't agree to anything, especially in writing, in hopes of somehow thinking that by giving in it will make her change her mind.
Don't confuse her willing to talk with your hopes of receptive. They will get crushed. Take care of yourself. We both know you'll go. Do what you have to do. Do what's for you, not what you perceive the "relationship" to be, because it isn't. Fair winds and following seas to you, my friend.
There are moments in this life when you are so confident in the rightness of your actions, that not even for a second do you consider the option that you might be wrong.