I believe that Microsoft continues to get more and more serious about the BI space and Excel will be the BI Product around which Microsoft will continue to build.  The last version of Excel saw some major improvements in the BI area around Pivot Tables.  The next version of Excel should see more improvements in this area.  When I read Rajan Chandras article entitled "Is Excel a Complete BI Solution?" in Intelligent Enterprise (http://www.intelligententerprise.com/blog/archives/2008/08/is_excel_a_comp.html) my answer was "look at Excel as part of the Microsoft BI stack".  SAP/BOBJ, Oracle/Hyperion, and IBM/Cognos have BI stacks and Microsoft’s BI stack is SQL Server (Analysis Services, Reporting Services, Integration Services) combined with Office (Excel and Performance Point Server).  With the consolidation in the BI space, Microsoft has to also move towards better integration of its various BI pieces.  With the ubiquity of Excel, it makes sense that Excel be the key to the Microsoft BI stack.  Microsoft needs to bring all the pieces together and have a BI stack that integrates well.  This will eventually happen.