One of the things that bothers me slightly in the reaction to Twilight is how many film bloggers who run in the same circles don't want to go see it. Many of them, I suspect, would like to be film critics one day beyond their own blog site. Having done that and continuing to do it, one of the important things is learning to write about films that are not up your alley. I understand the temptation to want to stick to films that give you intellectual red meat. At the same time, though, critics have to learn how to deal with all sorts of films. You have to be able to write an intelligent and/or witty pan just as effectively as a deeply intellectual rave about an art film.
Whether you like it or not, Twilight is a cultural phenomenon that says something about where we are. If it's not your thing, it's perfectly snicker-able material, so that it's entertaining either way. It's also tremendously fertile ground for writing a fun review. It also has some things that I honestly like about it. In fact, it wouldn't surprise me at all if I liked, or at least respected, the next outing. The ability to write about such a film is essential to the profession.