The key question behind Gemini is: how much value can an Excel user derive from Microsoft’s BI stack without having to pick up a book on OLAP, Dimensional Modeling or Analysis Services?

 New feature in SQL 2008R2 with which Excel user can build models, analysing data from Excel 2010 and  share it with others by uploading it to Sharepoint from Excel it self.....really cool feature know more about it at http://blogs.msdn.com/gemini/