Rav Beni Lau of Beit Morasha and Beit Knesset HaRamban has a nice parashat Hashavua piece about "הלכה בידוע שעשו שונא ליעקב"
It is here in Hebrew and here in English.
I particularly like the way in which he relates to the academic research. He talks about the way in which Talmudic research demonstrates that the classic quote is wrong!
"Talmudic scholars who identified with Rabbi Hirsch's (humanistic) Weltanschauung challenged the validity of the above-mentioned halakhic principle - רבי שמעון בן יוחי אומר הלכה בידוע שעשו שונא ליעקב - through a philological examination of the midrashic terminology, and made an amazing discovery: No manuscript of the Sifri (the source that mentions this subject first) contains the word halakha in that particular context. Instead, the text reads, 'והלא בידוע שעשו שונא ליעקב' - "After all, it is a well-known fact (vehalo beyadua) that Esau hates Jacob."
How did the word halakha creep into this text? Obviously, a simple graphic error occurred. The word vehalo והלא can be written in abbreviated form as 'והל - which a careless copier turned into halakha והלכה."
One might imagine then, that this particular Talmudic proverb has lost its validity, however Rav Lau concludes:
Although charming, this theory is irrelevant, because no philological study can ever overturn the axiomatic declaration that "according to halakha, it is a well-known fact that Esau hates Jacob." As long as there are world leaders like Iranian President Mahmoud Ahmadinejad, the pessimistic view that the gentiles will always hate the Jews will persist.