Very interested in this concept, I just am unclear how the interface & data can be separated in a way that is easy for spreadsheet users to understand. Users see the cell as the canonical data point, after all, they see all their data in front of them. Perhaps the problem isn't the interface but the way the underlying logic is hidden.

I'd be interested in discussing this more tomorrow, my email is my hn username @gmail if you want to hit me up when you have more details to share.