First things first: huge love, brimming-over-with-joy love, loud outburst crazy fantastic time-lord sort of love for the obvious reasons.
But I had a big problem with this episode, too.
So, outside the story, they decided that Jack should be left behind so that we could see how Rose deals with the Doctor's regeneration. Also, outside the story, John Barrowman isn't able to be part of the second season at all due to scheduling conflicts. This is all well and good.
Inside the story, the Doctor hasn't got a CLUE that Jack's died on that station. The Doctor and Rose are rather busy, see. (By the way, Jack is also busy, what with GIVING HIS LIFE to buy the Doctor time.) Then, as they speed away, crisis averted, they are kept busy with the Doctor's regenerating into David Tennant and also doing a nice thing for charity. The Doctor says something about Jack being okay and rebuilding the earth (boy, he got to work fast!), which could be part of the Doctor's special powers of magically sensing human deaths followed by amazing resurrections, or it could be the Doctor talking out of his Tardis. This is also well and good.
Then, we see Torchwood -- the place, and the series. Jack is a very sad person deep down. Yes, he is incredibly charming and quippy and clever and still the sexiest Captain Jack who wears a trench coat, but he's also full of loneliness, and yearning, and so many questions that he thinks only one man can answer. (He was angry and a little bitter, too, as we see in Utopia, which makes things even more poignant when you add that to how he was in the Torchwood series.) When he finally hears the sound of the Tardis again, a sound he has longed to hear since 1869 (too long for us ever to appreciate), the joy and hope in his face are heartbreaking. And this is very, very well and very, very good.
Fast forward at last to Utopia, and what do we see? The Doctor AND THE TARDIS trying to get away from Jack. WTF. The Doctor telling Jack that he "immediately" knew -- KNEW! -- that Jack came back "wrong." WTF. So not only does the Doctor in fact have special powers of knowing when people die and come back to life on complete other parts of giant orbital broadcasting stations, he can tell if they don't come back to life QUITE RIGHT. Even if this is true, where does he get off TELLING SOMEONE WHO WENT OUT FIGHTING FOR HIM and then was brought back through NO CONTROL OF HIS OWN, "Guess what buddy, I knew you came back all creepy and wrong and THAT'S WHY I LEFT YOU BEHIND"?
I mean, Jack basically tells you he's been waiting to meet up with you again for almost ONE HUNDRED AND FORTY YEARS, shows you that he felt hurt and abandoned and yet those feelings were secondary to the loyalty and love that he clearly still has for you and Rose, demonstrates that he's endured what no one would be equipped to endure and yet he is still -- in all the important ways -- warm and human. And now he's there, asking you, pleading with you, face to face. And you tell him your INSTINCT was to GET AWAY from him, and that's why you left? I'm sorry, but that is complete fucking bollocks. Even if who he is now IS "wrong," how is it in any way Jack's fault?
And you know what? I GET that whole "all things must end" thing that RTD keeps hammering at. Yeah, OF COURSE they must end, because, hello, living in the real world where physics operates, and it's not like there's really a choice in the matter. I ALSO get, even if I don't agree with, that whole trope** where struggling against this is "unnatural" or "evil" (or "wrong") and generally ends in bad things for all involved.
(**Which is also a stupid trope, because, again, IT'S NOT LIKE WE REALLY HAVE A CHOICE IN THE MATTER IN THE REAL WORLD. Like in School Reunion, where the Doctor is given an opportunity -- suggested to be a true opportunity -- to bring back his people and basically make the universe a place where there is always companionship and no suffering, and he TURNS IT DOWN because suffering makes us who we are? WHAT THE FUCKING FUCK. That's not a revelation, it's just life. Suffering defines people along with the good stuff, but that's because no one's been able to get rid of the suffering so far. It's just plain fucking stupid to contrive things so that your character is all "noble" for choosing the universe with death in it, so that we in the real world feel better about the only "choice" we actually have.)
But it is too much that in service to this trope, RTD has made the Doctor look like a heartless BASTARD who leaves friends behind and is cold when they reach out to him. We know that the Doctor is not all puppies and ponies, but in this episode he was made to be cruel to someone he's supposed to care about. THAT, if anything, is what's wrong. And as for Jack: I don't understand why RTD, having decided that this is what happened to Jack, would first of all fail to properly show any real empathy for him, and second of all take such a simplistic, cliched approach to where he fits in to a world-view in which all things must end. RTD is able to show so much faith and hope in humanity as a whole -- lasting as it does until the literal end of days -- and yet he seems to categorically deny true humanity to one man who individually might last forever.