Well obviously, we all want to know what happens to Gordon.  But then there's Barney Calhoun, Alyx, Eli, Dr. Kleiner, the g-man and many others.  Myself, I'd like to hear more about the g-man.  To me, he was alot more mysterious and interesting than any of the other characters in hl1, and you didn't know what his true motives/origins were.  He offered you a job at the end of the first game, thats all you know.  He could be working with or against you, playing you like a pawn, anything.  Thats what makes a good character to me, 95% of the g-man is still an enigma.  But I'd like to see more character development for Gordon as well.