Excel 2010 and up have the ability to read from web services that support Microsoft's OData protocol, and Microsoft is pushing some add-ons they built for Excel

Excel 2010 and up have the ability to read from web services that support Microsoft's OData protocol, and Microsoft is pushing some add-ons they built for Excel to turn it into a more robust front-end for business intelligence things. So I don't think it's about knowing Excel and knowing what an API is as much as that you can train someone to paste a URL in and then they can build their own reports/worksheets that join in your data.