I totally agree that this makes sense for certain types of Excel work -- the data analysis, report generating workflows. You can see my comment above about how we're addressing some of these issues with Mito.
However, not sure that these three points hold for the type of financial modelling work that is done in Excel today. There isn't a great unbundling of Excel for the LBO, etc world (yet), so the inability to save or have columns with multiple data types/formulas seems quite limiting for that world.
I was thinking that there were two types of worksheets. the current, freeform sheets, and in addition to that a new type that would enforce data integrity over columns. That would make it much safer to have worksheets for structured data and freeform sheets for visualizing etc separate.
(the first one was admittedly a bit tongue in cheek.)
However, not sure that these three points hold for the type of financial modelling work that is done in Excel today. There isn't a great unbundling of Excel for the LBO, etc world (yet), so the inability to save or have columns with multiple data types/formulas seems quite limiting for that world.