If you're wondering why Elena's brother Jeremy didn't kill Vicki to save her, like a good brother would, it turns out originally he was supposed to. They chose to have Stefan kill her because it enhances his status as the "hero" of the series. Plus, they couldn't justify Jeremy knowing how to kill a vampire. (Doesn't everybody know how?)
What's interesting is that while they were trying to establish Stefan as the hero, it turns out in the end that Damon was really the helpful one. He not only disposed of the body, but he whiped Jeremy's memory of the murder and replaced it with one that might give him closure. Elena may not have thanked him, but it's certainly the start of a more amicable relationship, which I'm really psyched to see. The main allure of Twilight for me is how a girl can be attracted to two different personalities: an exciting one and a safe one. Damon was kind of being a jerk, telling Elena that Vicki's death didn't mean anything to him—that none of these human interactions and consequences mean anything to him. Then he did this 1-80 and pretty much highlighted the benefits of having an evil boyfriend—cruel enough to dispose of a dead body and well-fed on enough human blood to make his memory-whiping powers extremely effective—as if to suggest that even though he's not Prince Charming, he is reliable.
But can she really trust Damon? Kayla Ewell, the actress who used to play Vicki, says that there's a chance she could come back. Since Stefan pulled the steak out of her chest and she didn't turn to dust, there's no telling what Damon did with her body or whether she can wake up. My hopes are actually for a different scenario. I find damsels in distress incredibly annoying. Stefan is all about coddling Elena, and I can't blame him. Vicki almost killed her, and this week a hostile, hot blonde visits for his birthday. She needs to learn how to defend herself, how to properly execute a vampire, and I think the only person who would teach her is Damon. I wouldn't advise it, because she could use it against him, but it could also be an excuse for them to get closer. I'm dying for him to make up an excuse. lol