Just the way we are able to upload a Power Pivot Model to SharePoint and then connect an Excel workbook to the model hosted on SharePoint (See http://www.powerpivotpro.com/wp-content/uploads/2015/07/SharePoint_PowerPivot_ToExcel.png) ... ...In a similar manner we should be able to connect Excel to a Data Model hosted on PowerBI.com. Bonus Points: If users can also connect to a Power BI Desktop file (.pbix) using Excel. This would perhaps more for testing or ad-hoc use. Similar to how when building an SSAS Tabular Model in Visual Studio, you can click "Analyze in Excel" to open an Excel window connected to the model you are working on. As an Excel user, I would love to use the cutting edge Data Modeling capabilities in Power BI Desktop (bi-directional relationships and new functionality rolled out each month). However, while the new Power BI offers great visualization options, Excel gridheads like me, just NEED to be able to create Excel Pivots off of the Power BI Data Model. If this could be enabled for Power BI, that would be very useful. - Either by connecting to a Power BI Model (.pbix) hosted on PowerBI.com (This would be similar to how I can create Excel Pivots connected to a PowerPivot Model uploaded to SharePoint) AND/OR - By connecting Excel directly to a .pbix file (like on your C: Drive) Without this functionality Power BI feels like a **One Way Journey**. Once I go from Excel/PowerPivot to Power BI Desktop, the only visualization options are those on Power BI. I may be looking at it from the wrong lens (still warming up to SaaS model of BI), but in my mind the "Data Model" should be agnostic of the visualization layer/tool. After building my data model, I should be able to connect any viz tool of my choice (pretty much). And that model already is in place for Power Pivot - by hostin your model on SharePoint or on SSAS Tabular server you can pretty much use the viz tool of your choice - Excel Charts/Pivots, Power View (within Excel or SharePoint), SSRS and other Microsoft and Non-Microsoft Viz tools. Whereas with Power BI, I feel like I would be locked in to the visualization experience on PowerBI.com. The whole visuals project (https://www.github.com/Microsoft/PowerBI-visuals) is great but not for everybody. Plus, if I am using a specific viz tool, I want to be able to continue using that. For many users that tool is Excel 🙂