With the Office 12 wave, we are taking the next logical step bringing these together to enable highly customizable solutions for data analysis and reporting.
The Excel team has created an engine that supports databinding, calculation and rendering of Excel workbooks on top of SharePoint. All HTML. No ActiveX. You see the data on the SharePoint page and (if you have permission) open it in the Excel client for your own analysis. This gives users a very flexible canvas using Excel's modelling, formatting and charting capabilities and more natural way to discover and analyze data. For more information, check out the Excel team's blog (I've linked to their server posts - start at the bottom as they cover a lot http://blogs.msdn.com/excel/archive/category/11361.aspx).
If you want Learn more about the technical beta. http://www.microsoft.com/office/preview/default.mspx
EROL MVP SPS