Here's an excellent SSC article by Johan Åhlén on building CEP (Complex Event Processing) solutions in SQL 2008. "What is StreamInsight and what is it good for? StreamInsight is a platform for developing and deploying applications that handle high-speed streaming data. It could be used for near real-time processing of data from production environments, structured data such as financial information and unstructured data such as Facebook, Twitter and blogs. Multiple sources can be combined and refined before they are being output. This technology is called CEP - complex event processing.
"Combine StreamInsight with data mining, and you can have real-time fraud detection, stock market prediction, you name it... Imagine a real-time Business Intelligence-application where the management can actually see the KPI gauges moving on the screen. I would say that monitoring real-time flow of information is one of the key success factors for tomorrow's Business Intelligence. This is also supported by Ralph Kimball, saying in an interview that Business Intelligence is moving from the strategic level towards operational level processes such as customer support, logistics and sales. At the operational level data must be continuously updated, not just once per day. I would add also that the new generation, that has grown up with Facebook and Twitter, will make it necessary to monitor new sources for successful Business Intelligence."