Vanessa Hudgens was in talks to star in a big screen reboot of Buffy the Vampire Slayer, which would have been more akin to the WB series starring Sarah Michelle Gellar than the original theatrical film, which starred Kristy Swanson. Hudgens decided against this new incarnation of the franchise because she felt it would be overkill at the height of The Twilight Saga's overwhelming popularity.
In an article from Showbiz Spy, it is noted that Sarah Michelle Gellar would have appeared on screen along side Hudgens. But now that the High School Musical star has politely stepped away, it seems that the entire project has been put on indefinite hold.
An inside source told the following to Showbiz Spy:
"She felt that with Twilight still so massive, Buffy would not be the best option right now. The idea was to have Sarah Michelle Gellar back but with Hudgens as a fresh, new character. The project has been shelved for now."
We will have more info on this story as it breaks.