The *only* glitch is the lack of an empty set notation. The idea of
dict() == {:}; set()=={};
which would be the obvious choice if starting fresh,
was considered but rejected by Guido as too disruptive
and introducing another barrier between Python 2 and 3.

I have to say that the *lack*of those two suggested literals are a sore point for me (that along with the fact that dict doesn't inherit from set).  Call me a nit-picker, but (without them) they are like sand in the vast gearbox of my mind when using python3: small but disruptive.  I would argue that the lack of them is what is *preventing* the adoption of python3.  And although I appreciate the kind reluctance to change the long-standing {} for the empty dict, I hasten to mention that the universe will naturally gravitate to that which is most elegant, so better to feel the pain at the beginning than a long demise without them.  (I suspect there would even be a small but measurable increase in downloads should python offer the option. )

Along those lines of simple ease-of-use issues, help() should have a verbose option, so that doctests don't clutter up basic interface information.  And I put another vote (from a discussion long ago) in favor of a test() built-in to make test-driven development a core part of the language.  This would be a quite novel and powerful step in front of any other known language.

Just some minor thoughts from nobody in particular  .... :)

marcos