See Add `OrderedSet` to stdlib for a discussion of adding an OrderedSet data structure into python stdlib. My takeaways from that thread about one specific data structure are:
1: most people think it would be nice to have this object in the stdlib if there was no cost to having it in there.
2: There needs to be some discussion about exactly how each implementation will look
3: The biggest hurdle is finding someone(s) with the bandwidth make and maintain an implementation for each of these data structures.