Debora Estrin made an interesting statement. The “early challenges” (the thousands or millions of randomly scattered sensor notes) do not have much applicability outside the battlefield. The new challenges are heterogeneity (specific sensors with specific capabilities) and interactivity (basically sense-making is a process where humans are involved). She made the point that the logical consequence is that dealing with data is the essential issue and statistics have an increasing role. Furthermore these new research directions make a stromg call for application driven research. With these very insightful comments she criticised a lot of the current work in sensor networks. Especially the observation that there is no such thing as a "general sensor" - it points out that concrete applications are required to make meaningful contributions, even to basic research in sensor networks research.