Starwars.com has posted the teaser trailer for Star Wars Episode III, "Revenge of the Sith".
The term "teaser trailer" is movie lingo for a short preview which doesn't really tell you much about the movie but shows some cool images and gives you the general theme. Teaser trailers usually come out about a half year before a big movie comes out to make the public aware that it is on the horizon. Then about two months before the movie the actual full-blown trailer comes out that reveals part of the plot. Then a couple of weeks before the movie comes out you start seeing short TV advertisements.
Why are they called "trailers"? A long time ago previews for new movies were shown *after* the feature presentation completed, rather than before. In other words, they trailed the main feature. The term has stuck even though the original meaning is now inaccurate.
Sort of like SOAP. Originally it stood for "Simple Object Access Protocol". Now according to the SOAP 1.2 specification:
In previous versions of this specification the SOAP name was an acronym. This is no longer the case.