If you were to go ask a really huge company what their roadmap for product x is most would say “That confidential for internal use only,” or something similar.
Now imagine how excited your customers could get if you tell them what you are going to do, and then they see those results?! That my friends is how you add to the customer loyalty bucket.
As an open enterprise it just makes sense to keep your Roadmaps open to the public as well.
Case Study: WSO2
WSO2 endeavors to be as open as possible inside the law. Coming from an Apache email list mindset, WSO2 has always taken the open approach, including their product roadmaps.