"Today’s business decision-makers have a distinct advantage over their predecessors when it comes to business intelligence (BI) tools that they can use for analysis, trending, and presentation of data. A good BI strategy, supported by a solid base of BI technologies, can streamline business processes while also boosting productivity and profit.
"The overall BI strategy of Microsoft comprises a suite of server and client-side data integration tools. Powerful analytical and reporting tools in SQL Server 2005 provide the backbone data management infrastructure, while Microsoft Office applications, specifically Microsoft Office Excel, provide the flexibility for information workers to remotely interact with centralized and secure data sources."
The article "Business Intelligence with SharePoint and Excel" (in the February 2009 issue of TechNet Magazine), explains how you can use Excel and Excel Services to analyze business intelligence data within SharePoint sites.