Remove an XXX comment to reflect final decisions.

I really need to review this PEP carefully before it can be marked
finished; I suspect there's a bit of creep between reality and the
PEP.

pep-0205.txt

@@ -195,13 +195,13 @@ Implementation Strategy
     participate, without taking a memory hit for numbers or other
     small types.
 
-    XXX -- Need to determine the exact list of standard types which
-    should support weak references.  This should include instances and
-    dictionaries.  Whether it should include strings, buffers, lists,
-    files, or sockets is debatable.
-
-    The implementation has already been added to the Python CVS
-    repository.
+    Standard types which support weak references include instances,
+    functions, and bound & unbound methods.  With the addition of
+    class types ("new-style classes") in Python 2.2, types grew
+    support for weak references.  Instances of class types are weakly
+    referencable if they have a base type which is weakly referencable,
+    the class not specify __slots__, or a slot is named __weakref__.
+    Generators also support weak references.
 
 
 Possible Applications