Can someone at ESRI address this question in more detail, or escalate the question to someone who is knowledgeable with the API? Is the Heat Map in Silverlight actually a point density analysis, much like that in the desktop spatial analysis toolbox. I understand that the intensity is a measure of cell size, but what about the search radius; is there a default not being revealed to the user? Also, does the heat map result get regenerated on each successive extent view or the entire feature extent?