There are both speed and correctness reasons for special methods being
looked up the way they are, so the behaviour isn't going to change.

Aside from providing additional details in the language reference on how
special methods are looked up (and the reasons things are done that
way), the only change that might eventually happen in this area is the
inclusion of a mixin class in the standard library to assist in writing
classes which delegate most operations to another object. That part
won't happen before 2.7/3.1 though (if it happens at all).