This post in ONTD had my thinking that there might be people out there, who haven't listened to The Potter Puppet Pals Adventure yet. This would be a grave mistake that has to be corrected!
Click click click click click Erm, it's all the same link, I just got overenthusiastic. Five songs, less minutes.
So, we got a new JKR interview:
If she looked inte the Mirror of Erised, Hermione would see the trio being well, after Voldemort is finished, and she would also see herself shagging Ron.
Some people are surprised by that because ... the deepest desire of her heart is supposed to be some job, or good grades on her NEWTs, or freedom for the annoying little house elves? (I'm not saying house elves rights are not important but they are definitely not the deepest desire of anyone's heart, who isn't a house elf, and as far as we know probably not even the deepest desire of any house elf themselves.)
Hermione has other desires besides a bloody career, thank god she's human (well, written to be, in any case). Plus she even has more personal desires than having her hero pal succeeding in his quest, although I'm sure she would agree that this is the priority right now.
Harry's deepest desire would obviously be destroying Voldemort, as he knows with every fibre of his body that he can never be free until Voldemort is gone, he knows that he will vanish from the face of earth himself, if Voldemort doesn't bite it, plus he wants revenge for his murdered parents and other people, who were close to him more than to anyone else, and mostly died exactly because of that.
Maybe he would see his friends being well, like Hermione, but I suppose he is really focused on the Voldemort thing. His heart can't be set on his own happiness until he saved his naked life and achieves freedom for himself and coincidentally the world at the same time.
(After Voldemort's death his deepest desire is probably going to be founding a family, because he never had one, or a house of his own, for the same reason, or probably just carefree fun, for, well, pretty much the same reason.)
Hermione is already free. She could go to France and open a bistro or to New Zealand to study biology and never look back, if she wanted to. She stays with Harry because she wants to and thinks it is important. She would be crazy to care about Voldemort as deeply as Harry in the depths of her soul, because it is not about her soul.
In the depths of her soul she wants romantic love. She has parents, she has friends, she has talent, health and a bright future if she survives(which is part of what the Mirror of Erised would show her).
What she doesn't have is a sex life and the man that she loves. What do you expect her to desire?
Ron would also see Hermione as his, although it would possibly feature her admiring him as a hero or him saving her or possibly the three of them being celebrated after Voldemort's demise and Hermione being proud of him, because he is still the sixth Weasley boy and not entirely sure if he is good enough. He knows that people, most importantly Hermione like him. He is easy to like and nobody has ever rejected him, not even the twins.
What he doesn't know is if they, and most importantly she, respect and admire him and I fully expect this to be the deepest desire of his heart.
Hermione is not afraid not to be respected. She always was. She has her own pressure to be perfect and better than anyone in school, but hot damn, this would be one pathetic deepest desire for a 17 year-old girl, who is going on a quest to save the world. Harry already rightly mocked her for her boggart.
She is a hero, but she doesn't feel the need, the desire, to prove herself as one, because again, nobody ever questioned her heroism. She is only a hero because she wants to do the right thing. The deepest desire of her heart would be about something she actually craves.
I realise that this is a way too long post in reaction to JKR making a naughty joke. :D I couldn't help myself.
ETA: Oh, and she confirmed Draco's redemption. (Actually that's the much more interesting point.)
Wow. It's not really surprising, but she didn't have to answer the question that way!
What happened: She was asked if Draco could redeem himself and answered, that he wouldn't have killed Dumbledore and we would have to wait and see what that means for his future.
That's quite direct.