Here’s a fun, detailed look back at the teasers and trailers from the prequels. I’ve written about them before but star wars.com has a lot more info and plenty of trivia:
Trivia: While we could see General Grievous already in the Tartakovsky Clone Wars series as early as April 2004, his movie look was something of a secret and he appears only in a far away shot on Utapau when Obi-Wan confronts him. Grievous’ bodyguard, the IG-100 MagnaGuard, does get a very clear shot in the trailer however.
Alternate shot: Ki-Adi-Mundi’s reaction to the clones aiming their weapons at him is different then what we saw in the movie. This is clearly seen with the background, which appears to be the Jedi Temple and not Mygeeto. In fact, the clones pointing the blaster to him are not even his clone troopers but rather the 501st troopers on Coruscant.