That script for The Twilight Saga: Eclipse that's being spread around the Internet? It is real, and it was based on a copy held by cast member Jackson Rathbone, who plays Jasper Hale in the vampire series. (Check out a copy of the front page below, which is clearly marked with Hale's name.)
That's the news from Deadline Hollywood. (We're not going to link to the script ourselves, but it's easy enough to find if you just Google it.)
Deadline Hollywood's Nikki Finke says it's not the final script:
Now I can confirm that it is an early version of the Eclipse script (not the shooting script) and it is Rathbone's (who probably left it behind at a blood bank). Does it matter? Of course not. Like duh, the script is based on Stephenie Meyer's bestselling book. Judging from New Moon's worldwide grosses of $682M so far, I say not even this copyright infringement can stop the Twilight Saga juggernaut.
The third Twilight movie has already wrapped production and will debut on June 30.
We're thinking Jackson may not be asked back for the fourth movie ... either that, or they'll make sure his copy of the script stays under lock and key.