Any idea that has not received any kudos within a year after posting will be automatically declined.
Several wires could be connected as selector inputs, and then named for example X, Y and Z, just like in the formula node. These variables X, Y and Z could then be used in formulas in the case selector labels.
The cases could then be for example "(X+Y) > Z", "X>Y" and "Default".
I guess that one major objection to this is that cases are not guaranteed to be unique. One solution to this could be to just select the first matching case.
A colleague of mine who is new to Labview came up with this idea this morning, after attending a Labview beginner's course.