I have the following as part of the patch for that issue:
---------------------------------------------------------
diff -r b668c409c10a Doc/reference/datamodel.rst
--- a/Doc/reference/datamodel.rst	Sat Dec 28 20:37:58 2013 +0100
+++ b/Doc/reference/datamodel.rst	Sun Dec 29 06:55:11 2013 -0800
@@ -2073,23 +2073,31 @@ left undefined.
       builtin: float
       builtin: round
 
    Called to implement the built-in functions :func:`complex`,
    :func:`int`, :func:`float` and :func:`round`.  Should return a value
    of the appropriate type.
 
 
 .. method:: object.__index__(self)
 
-   Called to implement :func:`operator.index`.  Also called whenever Python needs
-   an integer object (such as in slicing, or in the built-in :func:`bin`,
-   :func:`hex` and :func:`oct` functions). Must return an integer.
+   Called to implement :func:`operator.index`, and whenever Python needs to
+   losslessly convert the numeric object to an integer object (such as in
+   slicing, or in the built-in :func:`bin`, :func:`hex` and :func:`oct`
+   functions). Presence of this method indicates that the numeric object is
+   an integer type.  Must return an integer.
+
+   .. note::
+
+      When :meth:`__index__` is defined, :meth:`__int__` should also be defined,
+      and both shuld return the same value, in order to have a coherent integer
+      type class.
---------------------------------------------------------

If for some reason that patch doesn't make it into 3.4 I'll split the doc change off to its own issue, unless you think it should be split off anyway?