On traditional tables we have the ability to control whether the filter is visible by default or not. But to the best of my knowledge there is no way to configure that for any of the start center portlets.
It's unlikely for us to enhance the existing start center portlets at this point. We're creating dashboards built on our new UI framework in MAS right now and that would be where we would add it if we still needed it. I have seen mockups of KPIs, result sets, etc. but I haven't heard about anything related to bulletin board yet.