The multidimensional spreadsheet has been around for a long time. The first product I worked on was one, that competed with others like Lotus Improv, CA-Compete, and one for the Mac that I believe was named FreeBase. That Computer Associates and Lotus were selling them tells you something right away. I believe it was IRI that sold Javelin, a spreadsheet with some time-series capabilities. There are/were many others too. OLAP planning product (of which I’ve worked on multiple) tend to provide a very spreadsheet-ish outlook on their UI and modeling capabilities, coupled with real data management.