[xscott]

I completely agree and have been thinking the same thing for a while now. Another reason you need the function language to be really integrated with the rest of the spread sheet (unlike VBA) is so that global variables are also visible in the dependency tree and topological sort. For instance, imagine a cell containing the following lambda function:

    function (x, y) { return A1*x + y; }

It's clear that if the user changes the value in the A1 cell, any other cell which calls this function should be updated to reflect the new result. In addition to the arguments to the function (x and y), A1 is also an implicit parameter.