Thanks everyone for the input.
I am fortunate as we already have a rather active community which is
why I thought forums may be a great resource. I was thinking that I
could use the forums during and after a sprint as a way to get
opinions. Similar to Kev's experience we could present questions
focused to current sprint and possibly upcoming stories on backlog.
This way we might be able to avoid run away conversations. I was also
thinking that the user input can be helpful to define user stories.
I guess we can start small and see what feedback we get.