I must admit I'd grown fond of the little snot in a "love to hate" kind of a way, which is what Morrison had intended all along. That and making him the butt of innumerable in-jokes.
Damien's death was clearly intended to call back to that of Jason Todd, which I understand. And, unlike Jason's, I hope it sticks. See, to me, Jason's death was the last comic book death that had real impact, real force to it. It came before the excesses of the 90s through to today, when characters can be killed off en-masse for little to no consequence, or high-profile deaths that you know will be reversed. When he came back to life, well, it took a lot of that away.
So that's why I'm glad that he's dead. not because I disliked Damien, but because it's a chance to bring that back, to have a comic book death that means something again. This is not a spur of the moment thing; Grant Morrison has indicated that this was his plan for the little toerag all along, and that it was only other events that had kept him alive this long. This, I like, and I look forward to seeing where they go from there.
And personally, I'll allways remember Damien like this