There hasn't been anything quite like the hype ramping up towards James Cameron's first film in nearly twelve years. 20th Century Fox has even declared August 21st Avatar Day. What is that, exactly? The day audiences worldwide get their first taste of the new sci-fi mo-cap fantasy film, of course. The presentation will consist of the never-before-seen trailer and footage from the film that was previously screened for select crowds at Comic-Con 2009. Now, according to Apple, the online debut of the trailer has been moved ahead one day, to August 20th.

The Avatarcount down clock has even been updated to reflect the change. We now only have 4 days and counting until we're able to reveal in the magic that is James Cameron's latest opus. Starring Sam Worthington, Sigourney Weaver, Michelle Rodriguez, Zoe Saldana, and Giovanni Ribisi, the film follows the amazing adventures of ex-Marine Jake Sully as he becomes lost on an unexplored world full of amazing inhabitants. Word coming out of Comic-Con is that this immersive 3D film feels and looks like nothing ever seen before it.

The Avatar trailer hits this Thursday, August 20th. More footage from the film can be seen in IMAX on Avatar day, August 21st. And the full-length feature film will hit theaters on December 18th, 2009.