My opinion is I'd rather the market be saturated with carbon-copy teenage vampire novels and movies than teenage wizard novels. That's because I happen to like Harry Potter and, while there were definitely a large number of rip-offs of the Potter concept that came out after, there seems to be more of the teen vampire variety. And those rip-offs seem, as a whole, to be more annoying, to the point where it's having an adverse impact peoples opinions of earlier vampire-culture icons like Buffy, Moonlight and Forever Knight. (BTVS fans are already feeling this as a Twilight-inspired reboot without Joss Whedon is in the offing).
The Potter books and films seem to have avoided a lot of the negative-press of its league of ripoffs, and along the way even managed to get in a dig at Twilight (I do wonder if I'm the only one who caught the joke in Deathly Hallows about Twilight).
As for the OP, I feel for ya. Just 2 more years and Twilight will fade away, though. Just around the time the Hunger Games movies will have taken off, so we'll end up with a bunch of cash-in novels and movies all doing variations of Battle Royale, with teenagers killing each other for sport. I guess that's an improvement on vampires with teen angst, I suppose...
Alex