from __future__ import nested_scopes
I this this alternative better since there is only one "reserved" module name.
I still think releasing 2.0.1 with warnings is a good idea. OTOH, maybe its hard for that compiler to detect questionable code.
The problem is that in order to do a decent job of compile-time warnings, not only the warnings module and API would have to be retrofitted in 2.0.1, but also the entire new compiler, which has the symbol table needed to be able to detect the situations we want to warn about. --Guido van Rossum (home page: http://www.python.org/~guido/)