See here for the official release.
The other two finalists are are Javon Ringer of Michigan State and Shonn Greene of Iowa.
The winner is announced on December 11th and the award in officially presented on February 6th, 2009.
All three of the finalists have impressive stats. While Greene and Ringer has more yards and TDs (as of now), Knowshon is the most high profile name of the three. With a big showing against NATS, Knowshon has a really good chance at taking this award.
Garrison Heart is the only other Doak Walker Award winner from UGA.
h/t to David Hale.