WILL: Henslowe, you have no soul, so how can you understand the emptiness that seeks a soul mate?
This line accomplishes a lot early in the film. It establishes Henslowe as a person who is decidedly not a romantic, and Shakespeare (in case you've never heard of him) as a person who is romantic, and might be in search of a soulmate. We have a feeling he'll find her.
DR. MOTH: So now you are free to love.
WILL: Yet cannot love or write it.
Shakespeare is a mastery of dramatic irony, and it appears that he lived is as well as wrote it. At least he did when he was writing. Here we see that he can create love on the page, but not in his real life.
VIOLA: All the men at court are without poetry. If they look at me they see my father's fortune. I will have poetry in my life. And adventure. And love. Love above all. […] No, not the artful postures of love, but love that overthrows life. Unbiddable, ungovernable, like a riot in the heart, and nothing to be done, come ruin or rapture. Love like there has never been in a play.
Even if Viola weren't played by Gwyneth Paltrow and on the poster, we would know here that she is the romantic soulmate Will is searching for. Her philosophy on what love should be seems to perfectly line up with his.
VIOLA: I do not love you, my lord.
Sadly, for Viola, her father and Lord Wessex do not care that she doesn't love Wessex. At this time, marriage is more often a business transaction before it is a declaration of love.
WILL: Love denied blights the soul we owe to God! So tell my lady, William Shakespeare waits for her in the garden!
"Love denied" is what Will is feeling toward Viola here, and that becomes a major theme of the play Romeo and Juliet as well. Both Will and Romeo are of a lower class than Viola and Juliet, and dramatic tension results because of it.
VIOLA: I would not have thought it. There is something better than a play.
Viola says this after her first night of doin' it with Will. Either he was really good, or she's only seen some average plays over the years.
VIOLA: I love you, Will. Beyond poetry.
Before Viola met Will, poetry was the biggest part of her life. Will came along and dethroned it, placing love in the number one spot. Shakespeare tends to believe that love will conquer all, so it makes sense that Viola has such a passionate reaction.