What a refreshingly interesting question! I absolutely adored doing the research as well as the resulting thoughts which ensued! In short, Kate Middleton's bouquet is the EXACT OPPOSITE of Ophelia's bouquet, ... and we hope that it will produce a much happier match in marriage as well, of course.
At first glance, none of the flowers match up at all, so allow me to guide you through my zany thought process here. Let's begin with looking at the flowers. Ophelia's bouquet contains rosemary, pansies, fennel, columbines, rue, daisy, and NO violets. Kate's includes lily-of-the-valley, sweet William (ha!), hyacinth, ivy, and myrtle.
Now for the ever-important meanings. Let's start with Ophelia's exact words:
There's rosemary, that's for remembrance. Pray you, love, remember. An there is pansies, that's for thoughts. ... There's fennel for you, and columbines. There's rue for you, and here's some for me. ... There's a daisy. I would give you some violets, but they withered all when my father died.
Ophelia doesn't give all explanation here (the poor dear), but if my memory serves me correctly, the remembrance of rosemary is to remember the DEAD and not the living. Further, fennel often stands for infidelity and columbines stand for lack of sincerity. (Yuck!) The daisy that I remember so well as the "friendliest flower" is named so because it stands for love that is forsaken, or not leading to marriage. Rue is for sorrow or, as I like to say, regret. Violets that Ophelia nixes from her bouquet stand for faithfulness, ... ah, let's nix the one positive thing, shall we?
Now let's look at Kate Middleton's bouquet (according to CBS News, by the way):
The lily-of-valley represents the return of happiness; sweet William means gallantry; hyacinth is for the constancy of love. Both ivy and myrtle represent both love and marriage. In fact, myrtle is the emblem of marriage.
Both ladies carry five flowers of sorts that correspond, ... if you take out Ophelia's rosemary for remembrance (Kate would never have included a remembrance of the dead in her bouquet) and her pansies for thoughts (did Kate not think at all? Ha!). You will find ALL the other flowers correspond as exact opposites: infidelity/marital fidelity, insincerity/gallantry, forsaken love/constant love, unfaithfulness/marriage and sorrow/happiness. Phenomenal!
Although I highly doubt the paradoxes above were planned by Kate, the meanings speak for themselves. In conclusion, I wish Kate and William all of the warmth, love, and faithfulness of a long and happy marriage, ... and I'll reiterate that hope is reflected in Kate having the EXACT opposite bouquet as Ophelia. R.I.P.