Anyone tackling A Midsummer Night's Dream has to, at some point, tackle the thorny issue of Demetrius.  At the beginning of the play, he is betrothed to Hermia, with her father's approval, despite having "made love to Nedar's daughter, Helena" (I.i.107).  By the end of the play, however, he is married to Helena and vows that he "will for evermore true to" her" (IV.i.175).  We have three paired sets of newlyweds, but Demetrius is the only character with an object of desire that changes (and stays changed) over the course of the play, the only one who loves a different person at the end than he does at the beginning.

So the question is this: despite the happy (or at least joyous) ending of the play, is the fate of Demetrius one to merit pity or joy?

When he first speaks to Hermia, his are not words of love, but of law, of privilege:

Relent, sweet Hermia, and, Lysander, yield
Thy crazed title to my certain right.

-- I.i.91-92

He simply wants what has been promised to him, a marriage.  There is no discussion of love.  Even when confronted with the revelation of his past liaison with Helena, he says nothing; he does not (cannot?) deny it.  When Helena speaks of Demetrius' feelings, she only states that "Demetrius loves (Hermia's) fair" (I.i.182); even she knows that it's not Hermia that he loves, but what makes her fair (some critics attribute this to complexion or race, but it could also be money, power, status).  Already, we begin to wonder of his true loyalties.

When we see him with Helena in pursuit, he tells her,

I love thee not; therefore pursue me not.
Where is Lysander and fair Hermia?
The one I'll slay, the other slayeth me.
Thou told'st me they were stolen unto this wood;
And here am I, and wood within this wood,
Because I cannot meet my Hermia.
Hence, get thee gone, and follow me no more.

--II.i.188-194

While he tells Helena that he doesn't love her, neither does he say that he loves Hermia.  Hermia may "slayeth" him, we also get the feeling that all of this stems from a perceived pre-marital ownership, as he refers to her only as "my Hermia."  Even what he continues to tell Helena puts into question his emotional state:

Do I entice you? do I speak you fair?
Or, rather, do I not in plainest truth
Tell you, I do not, nor I cannot love you?
...
Tempt not too much the hatred of my spirit,
For I am sick when I do look on thee.

-- II.i.199-201, 211-212

While he does state that he does not love Helena, he expands upon that, saying he "cannot love" her, perhaps because of his marital agreement.  Does he feel remorse for this?  Could this be the reason why he is "sick when (he does) look on" her?

Later, when Theseus finds the lovers in the woods, and Egeus calls Demetrius to take what is rightfully his (Hermia), Demetrius states:

My lord, fair Helen told me of their stealth,
Of this their purpose hither to this wood,
And I in fury hither followed them,
Fair Helena in fancy following me.
But, my good lord, I wot not by what power-—
But by some power it is--my love to Hermia,
Melted as the snow, seems to me now
As the remembrance of an idle gaud
Which in my childhood I did dote upon,
And all the faith, the virtue of my heart,
The object and the pleasure of mine eye,
Is only Helena. To her, my lord,
Was I betrothed ere I saw Hermia,
But, like in sickness, did I loathe this food;
But, as in health, come to my natural taste,
Now I do wish it, love it, long for it,
And will for evermore be true to it.

-- IV.i.159-175

Yes, he is still under the spell of the pansy potion, but there is nothing in the speech that is false.  He had been "betrothed" to Helena before Hermia (the result of his having "made love" to Helena?).  He admits to once having a love for Hermia, but he now seems to equate that love to "an idle gaud // Which in (his) childhood (he) did dote upon," in a reference to 1 Corinthians 13:11

When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put childish ways behind me.

But now, he says, he has returned to his "natural taste."  He has become a man.

Could the promise of riches, status, and marriage be the socially acceptable version of the pansy potion, making a boy "madly dote" (II.i.171) on that which normally makes no difference whatsoever to a man?  Could this then mean that the pansy potion has "corrected" the effects of Egeus' "prestige potion" of a marriage arrangement?

Some have argued that the ending of Midsummer is actually sad and tragic, in that Demetrius is no longer feeling his true feelings (since he's still under the pansy potion's effects).  Sure, it can be played that way.  Or it can be simply ignored (as many productions do).  But I think there's another way to play this: Demetrius first loved Helena, then abandoned that love for the promise of status and money, and only by the pansy potion is returned to his "natural taste."  And that way the ending truly is magical, joyous… and happy.

[of course, the problem is how to present this onstage... in some kind of pre-play tableau?  i don't know... i just don't know...]