This isn't a specific what but more of a "how" and I'm not going to suggest how it could be addressed nor do I know if it has already been suggested, addressed, or used.
I know the Bureau has put out some interesting projects to enhance readability of data. I was wondering if some form of advanced tool-tip mapping could be done on mouse-over. Obviously mouse-over is common but I also know that "within a circle of given radius" is also of interest. Could it be useful to create a mapping system which combines estimates within an aggregated/adjusted circular region as given by some input or sliding-scale radius?
I admit this is more of a "how" than a "what" but it did come to mind. For all I know there already exists such a product.