They came back!
After two weeks wondering if I had simply scared them off, I received a knock on the door this morning. One of the JWs was back, but with her husband this time. She was sick, which explains the absence of 2 weeks.
We talked about some of my beliefs, and some of their beliefs. We touched on the bible a bit, but not too much. They recognized that without first having a trust that the bible is the word of God it wouldn't do much good to just tell me what it says. We talked a little about the problem of evil, about epistemology and skepticism, about science and philosophy. The Watchtower they gave me last time had an article on Plato, which I had to bring up. I think we will get into evolution at some point. The JWs are old earth creationists, but one of the things we talked about is how the bible is scientifically accurate. Something there doesn't quite compute, so we'll see what develops.
I told them that I didn't want to waste their time, but I would be happy to keep meeting with them as long as they wanted to do it. I hope that they enjoy our interactions as much as I am so far. It doesn't appear they have any illusions about converting me, but we'll see how that goes. They gave me a book called "The Bible - God's Word Or Man's?" I don't think I will learn much from it (I studied that stuff for years), but I will read it throughout the week. It will give us some things to discuss when we talk next time.