I don't know about you guys, but I'm not worried about New Moon (or the other books) not being made into a film after Twilight. Millions of people have read the books and millions more, whether they've read the book or not, are anxiously waiting to see the film (I'll bet a good majority, more than once). I am so cocky about Twilight doing well that it's almost unbelievable. Critics out there who think Twilight is going to bomb... they probably failed third grade math. TWILIGHT IS FREAKING HUGE and it's only going to explode once the film comes to theaters. I'll bet my left leg it's bigger than Harry Potter and that it banks more than Order of Phoenix did in the weekend box office ($77 million). In fact, I bet it will surpass that in an EPIC landslide.
There's been loads of promotion, merchandise, the Hot Topic Tour, Comic Con, the Film Festival, websites, there are the fans themselves, and not to mention the hype that surrounds Bella and Edward. Even if someone has only seen the trailer, people are curious. They're going to go see this film.
I get that Catherine Hardwicke doesn't want to get everyone's hopes up - if by some horrible chance that the earth experiences apocalypse and every theater on the planet is destroyed - by not saying, oh yeah, definitely. I know Twilight's huge. There will definitely be more films. Her modesty is honorable, but I mean... she has to know how... (is there a better word besides "EPICLY FUGKING HUGE") her world is about to turn on it's axis with the PHENOMENON that is TWILIGHT.
An after thought: Honestly, if I had to bet, I say Twilight makes 100 million weekend box office, easily.