So many things are happening in this story. First is Katharine Hepburn's unexpected win - having just won the previous year for Guess Who's Coming to Dinner?, she became that rarity: the consecutive champion (fitting, too, that the first actor to pull it off was none other than Spencer Tracy). Second is Barbra Streisand's somewhat unexpected win - I say "somewhat" because post hoc, people have accepted that her win happened because of Babs' early admission into the Academy allowed her to vote for herself, therefore leading to a tie; the implication being that it would have been Hepburn's had Streisand not been voting, ignoring the fact that consecutive wins are, as I said, rare, and Streisand was dominating the circuit all year.
Third: the total dismissal, historically, of the three other performances nominated this year, including Patricia Neal's return to film after her strokes and Joanne Woodward's reminding everyone that, yeah, she's got it. Let's give everyone their due, shall we?