Despite the fact that Lucas defenders will claim this stuff isn't technically canon is really irrelevant. (I mean, who really considers the prequels canon anyway? Sheesh!)

Anyways, my point is, that canon or no, all of this stuff - the transcript published in Rinzler's book, the original RotJ script, etc. - all still points to the same thing. That the original tales of Anakin's downfall, his fight with Obi-wan, him not knowing of the pregnancy, Owen Lars being Kenobi's estranged brother - was the tale that Lucas and Kasdan and Kurtz built the Original Trilogy films upon. It's obvious this is exactly what they thought the backstory was all along - and it came from the big Gungan mouth of old George Lucas the whole time. Just cause he changes his mind in 1999 and starts revamping his original ideas doesn't make it any less true or any less obvious that it used to be this way.

Not to mention, it fits perfectly with everything we've seen in the OT, and is also a much more compelling and interesting backdrop than the garbage Lucas crafted for the prequels IMHO.