If this is done, it should be done with aspects of both Twilight and TrueBlood, so it will survive.
Yes, Buffy did Vampires before Vampires were cool and Buffy was NEVER cool, except for the British guy (and then he had a breakout and amazing role in the cult blockbuster REPO: THE GENETIC OPERA,a long with SpyKids girl, Sarah Brightman and Paris Hilton in the best roles of their lives and will never have better ones. Ever).
Unless you people and the rest of yuppie hipster nazi muslim commie redneck AMERICA (and all subsidiary countries that we own--- Egypt, Cuba, Texas, Saudi Arabia, Iran, Vietnam, Cambodia, Cincinnati, Madagascar, Ireland and whatever land/state/country/plane of existence Tay Diggs lives on) accept that VAMPIRES ARE FOREVER CHANGED FOR THE BETTER BY STEPHANIE MYER, you will live half-lives similar to those of Frank Castle and Jean ClaudeVanDame (after The Expendables and refusing to be in it). GET OVER THIS FACT, my collegiate level masochistic friends.
Buffy + Twilight Vampires would be an epic undertaking that would basically equate to a Marvel level Crossover.
LOOK AT THE POSSIBILITIES.
Not to mention Buffy is published by Marvel now anyway... so we're talking Blade and all sorts of useless Marvel characters no one cares about (Runaways, Thunderbolts, Iron Man) all showing up to fight Edward Cullen and that one chick with the short hipster hair who is probably one of the most important literary characters of all time (<3).
And if you don't understand what I'm saying, you must not be enlightened and most likely a communist.