One could almost ignore all of the other deaths and call it coincidence and circumstance, but Charity's death brings home the concept of the Judas Kiss.
I love the fact that Harry doesn't push the issue - that he loves Severus enough to live without the bread and butter of most relationships, even more so than 'The Declaration'.
Somehow, I want to believe that since Harry is master of death, he's exempt.
This is a haunting concept - beautifully executed.