How does Shakespeare make the balcony scene such a powerful and dramatic scene in Romeo and Juliet?

One of the most favorite scenes in dramatic history, the balcony scene in Romeo and Juliet is powerful and dramatic for many reasons.  First, the audience sees Juliet openly stating her love for Romeo; however, she has no idea that he is hiding below the balcony and can hear every word she is saying about him.  Secondly, both realize the ridiculousness of the reud between the Montagues and the Capulets.  One can assume that before this night, both Romeo and Juliet viewed each other's family as being disgraceful, ignorant, etc.  However, now that they have met each other, they know that the feud is of no importance.  This is also a powerful scene because Romeo is risking his life in an attempt to get just a glimpse from Juliet.  He knows that if the wrong person should see him, he will be in big trouble.  He is so taken with Juliet, though, that he does not care.  And when he finally sees Juliet, his metaphor comparing Juliet to the sun is one of the most cited romantic lines in drama.  This is also where their plan to secretly wed starts to take formation, as Romeo leaves after Juliet promises to get in touch with him the next day.