Of all the reproductions I have seen that take a little liberty to change something like setting or era, Luhrmann does pretty good sticking to original text.
One of his biggest liberties is the final scene. We never see Paris or the Friar and Juliet discuss the fight scene that occurs between Romeo and Paris. We do not get to see Paris' page or Balthazar outside watching out for anyone to come and check on the monument.
Throughout the rest of the movie, Luhrmann often portrays character lines through actions (we never see the word play of Gregory and Sampson in the beginning scene), the television news, or a different character. He also re-orders some lines, although he does stay true to Shakespeare's old English.