Funny send up of Twilight: New Moon involving internet memesTwilight is Mormon/True Love Waits meets vampires. It is vampires written from the point of someone who doesn't know about vampires.
Vampires are supposed to be immoral or amoral - because they have escaped death, they have escaped the threat of damnation, most often because they are already damned, irreparably.
Vampires are supposed to have a high libido. The exchange of blood is analogous to sex and the exchange of bodily fluids. That the male (usually) is taking this from the female (usually) is seen as taking of innocence/defloration. That the vampire requires this to survive is a testament to the rampaging libido of the masculine gender and the hunter/prey undercurrent that a lot of flirting skirts.
Vampires are supposed to be seeking something they once lost. In some ways, it may be their innocence and purity, which again goes to defloration, but also it could be a metaphor for the passion of new love against the comfort of old love. Choosing the vampire rather than the nice bookkeeper is choosing the affair over the warm but not dangerous love at home.
True Blood/Sookie Stackhouse does a far better job, as did most of Anne Rice. I LOVED when the virginal vampire has sex for the first time, and then the second time, and the resultant complications from having been turned as a virgin.
And they have weres and shape shifters in the Sookie Stackhouse books.
My sister is into Twilight, but at least she also reads Sookie Stackhouse...
Also, on a disturbing note given the last sentence, there is a toy (thanks to Taamar for the info) called the vamp which sparkles and you can chill for the more 'lifelike' experience. *shakes head*