After more thought, put me down for -1 on this proposal.   

I use pprint() quite a bit when teaching Python courses.  I expect that 100% of the time that users are following the live examples, I will get stopped and asked why their output is different from mine.

Also, I question the usefulness of the auto-resizing.  When I pprint a dir() listing or some such, the intended effect is almost always that I want a vertical presentation.  If a horizontal one-liner was desired, I would have used print() instead.  ISTM, this proposal is out of touch with the actual needs and desires of users.

As a reference point, consider that IPython pretty prints output by default and is not terminal width sensitive.