Usually a good thing:

Catholics, Reformed Christian Churches sign document recognizing common baptism

I think it's always good to look at what we hold in common while really recognizing what divides us. There are real differences in belief between Christian denominations, we cannot ignore them. However, that does not mean that we have nothing to talk about.

I think that I can safely say that without the influence of my non-Catholic friends in college, I would not be in seminary today. Being able to discuss our faith (and where we differed) in a friendly manner helped me learn more about my faith and led me to love it even more. We always knew that, even when we strongly disagreed, we were still friends and fellow brothers and sisters in Christ.