Well to be perfectly honest, D/G fanfiction is truly some of the best out there. I've read other pairings, but there's just something about these two that works in the fanfiction world, I think it's because you can come at it from so many angles. Since the characters are slightly underdeveloped at times in the books, you can really do things with the characters.
And Harry, I think it would fit if he were a bachelor in the end. All his role models were.
Spoiler:
Perhaps the look was because Pansy and Draco had talked of Ginny before? Maybe I'm reaching, but I could see him looking toward Ginny before they got on the train and Pansy noticing and worrying. I sort of hope that this ship gets way in book seven. Perhaps...Ginny gets taken and Draco is there?
I have no idea and I think I've read one to many fics about these two. I even had a dream with them a couple of nights ago!