The media can switch very easily. Twilight is hot right now, and I am sure HP will be once the movie is out.
To be honest, People are sick of waiting for the 6th movie right now. I am part of the real Harry Potter generation, where we were able to read the first book (experience the Potter Mania) and enjoy HP all the way through the seven books while still being at an age where we could do it without people thinking we were immature (bad reason, us Potter fans would see every movie and enjoy every piece of lit that J.K. Rowling Puts out no matter the age). It's the fact tat the Harry Potter books came out in a timely fashion, (the last book came out in summer of 07, I graduated in 08) The movies aren't coming out in that range though. I had a discussion with some of my friends, we said that it will be embarrassing to go to a child's movie. Especially since the last movie is looking like it will come out when we are about 22 or more.
Plus, Anne Rice books were the hot thing before Harry potter, it's a generation thing. The Anne Rice lovers didn't get Harry Potter Mania when it came out. HP maniacs doing get the new Generation of Twilight.
Twilight has sex appeal, it's a little more grown up with still that fantasy element to it. Harry Potter is generally a child's/tween book, even though the characters grow up and do have boyfriends and girlfriends, we don't see that real chemistry... it's skipped over really, which needs to happen when it is a child's/tween book.
I can that Harry Potter is a completely new world. Unless you read them very intently that you will get lost, some people just don't get it until the Harry Potter movie comes out just because 75% of people learn visually.
Twilight is for 13-up. I do admit it's kind of ridiculous, though. What I don't like is these eleven year olds saying that Edward is sexy and other stuff like that, because they don't know what 'sexy' and other stuff like that is.
Especially when people are Mulling Robert Pattinson because they are convinced he is the REAL Edward.
People also like Edward Cullen because he is the idealistic real guy. He is gentlemanly, nice yet rebellious, and protective. Girls like it when a guy will punch out another when he looks at his girl wrong. Edward Cullen is any girls fantasy, and he seems more real than Harry Potter who is in this Magical world, when Edward Cullen Lives in Washington State, Forks. (Which in itself I can't fathom because I have been to forks many times and La Push beach, and it's nothing special. Yet people from all over the world come to Washington, Forks mind you. Just yesterday I met people from Australia who were here for the Forks tour.)
If I come off as a Fan girl, I don't mean too. I have had no sleep, and I am hopped up on caffeine, which is making my limbs shake. :)
I just like the books (HP and Twilight), just because they are effortless reads. It's fun to just escape for a while, especially from college life and jump back in to the child like mind frame for a while.
If you haven't read the twilight books, you should. Because then you can have a more broadened perceptive of your own question rather than this very narrow-minded one.
If you did read the books, they are not everyone's cup of tea. I do find Bella rather needy, and Edward a little unrealistically protective. I mean if he had his way, he would but Bella in a bubble (Don't you remember Bubble boy? Like that).