Confused about nested scoping

[Stephen R. Figgins]

I seem to be misunderstanding what nested scopes do. 

>From AMK's summary of 2.1 changes: 

  Put simply, when a given variable name is not assigned a value
  within a function (by an assignment, or the def, class, or import
  statements), references to the variable will be looked up in the
  local namespace of the enclosing scope. 

Here is what I tried: 

from __future__ import nested_scopes

def printspam():
	print "spam has value %s" % (spam)

def scopetest():
        spam = 'bacon'
	printspam()

spam = 'eggs'
printspam()
scopetest()


I figured without nested scopes I would get 

  spam has value eggs
  spam has value eggs

But I thought with nested scopes I would get 

  spam has value eggs
  spam has value bacon

Because the second printspam's enclosing scope would be that of
scopetest in which I had reassigned spam.

But I still get eggs with my spam.

What am I misunderstanding?

-Stephen