HALO 3 script leak?

I looked at the first few pages of this alleged Halo 3 script by Joe Staten and it looks to be legit. It's formatted properly and all that and is written pretty well but I couldn't look at it too long. The hint of spoilers began to burn my eyes and melt my skull. Doesn't anyone know if this is legit? It's only 119 pages. Wasn't the Halo 2 script longer than that (as mentioned in the DVD that accompanied the Halo 2 special edition game)? Get the script here.

 

Here's a snippet from the beginning of the doc (spoilers?):

 

 

Halo 3

by

Joseph Staten
(Staten, 12/05/2004)

R Dft 4 //
CAMPAIGN MISSION: ABSOLUTION

FADE FROM WHITE

EXT. OUTER SPACE
A backdrop of blackness, with only small pinholes of light is
pierced by a massive, burning space cruiser. The large craft
is aflame in its rear compartments and appears to be under
attack. In pursuit...there is nothing. The cruiser is
unorthodox, with large, narrow extensions. Extremely angular
and geometric, it is certainly alien in origin. The ship is
Cessation.

PAN RIGHT (following cruiser)

Now a large, luminous blue-green planet fills the void of
space and the cruiser appears to head toward it, suffering
from interior ruptures and still reeling from what appears to
have been a violent attack. The flames are pearl-white gashes
of plasma gushing from various breaches along the rear
sections of the main hull. Cessations state is dire.