SpiritualGangster said: "The scene in the trailer where Bernardo refers to the apartment as his leads me to believe that Bernardo and Maria share it and that they do not live with their parents or that Bernardo and Anita live together and Maria is rooming with them perhaps?"
I noticed this myself. It seems as if Maria's parents might not be in the picture in this version, but if that's the case I think it works pretty well. It ratchets up the impact of the murder...Maria loses not only her beloved older brother, but the only father figure she has. (BTW, according to IMDB this version gives Maria and Bernardo a surname...Vasquez.)
I gotta say, I also like that Maria talks back to Bernardo, reminding him that she's of age and has a say in her own life. With both of these elements in mind...I wonder if the "arranged-marriage-to-Chino" is still a thing, or if Chino's just going to be a suitor without the implied arranged marriage? You know, something along the lines of "Chino really likes you, querida, and he's a good man...give him a chance and go to this dance with him." I never thought to question it as a kid, but as I got older I always did wonder...if Maria's parents were so old-fashioned that they wanted to arrange their daughter's marriage, how come they were fine with Bernardo choosing his own partner? And for that matter, none of the other girls in Maria's circle seemed to be subjected to this. It did seem like one element from Romeo and Juliet that was rather anachronistic in the twentieth-century version.
One thing I hope Spielberg has done: make it clear that the Prologue is taking place over several weeks or months. In the stage script, the Prologue is subtitled "The Months Before" and the stage directions bear this out--this is supposed to be an abstract representation, in music and dance, of an escalating conflict that's built up over a couple-three months, from the arrival of these first Puerto Rican immigrants to the actual start of our story, from minor skirmishes to an all-out brawl. The 1961 movie, according to the shooting script, was supposed to take advantage of the medium of film and convey this by showing the gangs in different changes of clothes as the Prologue went on, and by cutting from day to night to day again with each clash that broke out. But for some reason they scrapped this, not even showing the gangs in different clothes, and you got the (mistaken) impression that the whole conflict started and escalated in a single day. So I hope Spielberg takes advantage of the opportunities film gives him and conveys the passage of time during the Prologue.