ChicknDuck: So the "rewritten story" is basically a different translation but the same gameplay/videos/etc?
One of the developers (the writer, if I remember correctly) covered some of the major differences on Ice-Pick Lodge's forum for the game:
http://forum.ice-pick.com/viewtopic.php?f=28&t=9043#p94905 And the patch ads English subtitles for the Russian audio, trying to be as close as possible?
That is my understanding of it, though I must admit I have had no cause/desire to go back and play it with the patch (I'm among a small number who aren't displeased by the game's English version, I guess).