I still believe you are talking different things. My "expectation" is derived from these axioms:
* Macro is a local source-code transformation that replaces macro call with the macro definition (with some hygienic magic, if you prefer).
* The language adopts applicative order.
If you want redefining foo to affect the value of the closed variable 'x', then either you have a non-trivial definition of macros (macro transformation requires transformation of code surrounding the macro call) or you are adopting different evaluation semantics (like x is bound by call-by-name).
Note that your problem occurs even foo is a procedure. It's not a macro problem. It's a problem of semantics of closed variables.
