I've read books before where the normal Vampire weaknesses either weren't there or were largeely diluted. One book series (maybe by RL Stein?) had the Vampire able to go out during the day, but her powers were greatly diminished.
As for the movie, a little research shows that Edward is being played by the kid that played Cedric Diggory in Goblet of Fire; and the girl playing Bella has ben in a few more well-known movies like Jumper, Into the Wild, Zathura, and Cold Creek Manor.