I've implemented the proposal, as far as the pydoc modifications. See http://sourceforge.net/tracker/index.php?func=detail&aid=936774&group_id=5470&atid=305470.
3) extend the __slots__ handler to set the descriptor's doc string
to dictionary values if the slot's value is a dictionary.
I haven't implemented this, because I don't know a thing about Python's C interface. If someone more able would knock off a prototype, I would be grateful.