Es gibt wieder eine neue Beschreibungt und diesesmal ist es keine Spekulation.
I just had the honor to watch the teaser trailer for Revenge of the Sith, oh about 10 times in a row and I'll probably watch it another 10 times, and let me say that it blew me away. The description of the trailer floating around the Web is 99.9% correct. The trailer does begin with "A long time ago, in a galaxy far, far way." and includes Alec Guiness famous line "A young Jedi named Darth Vader, who was a pupil of mine until he turned to evil, helped the Empire hunt down and destroy the Jedi knights. He betrayed and murdered your father."
Some awesome highlights I should point out include a hooded Anakin with glowing red eyes - much like Darth Maul's, a scene of the Emperor wielding a lightsaber, I'm assuming during his battle with Yoda, which looks like he is throwing across the room. In what seems to be a full out war over Coruscant we see an early prototype of the X-Wing fighter with an extra wing cutting across the fighter and a curved nose. There's also a shot of a group of Wookies lead by Chewbacca getting ready to attack. We also hear James Earl Jones speak as Vader though his voice is a slight different then we are used to hearing in the original trilogy.
Let me say that the very first glimpse you see as Vader rises is jaw dropping. I highly recommending setting your TIVO to capture this because you will be wanting to pause and go back to the quick montage.