Below are three pics that I found online dealing with Episode III. The one on the left, taken from a British newspaper, is of Anakin Skywalker after he is burnt from lava after the big lightsaber duel with Obi-Wan Kenobi, and the photo to the right is of the Jedi killer General Grievous...how he is gonna look in the movie...not of his crappy animated version that fans will soon see on the Cartoon Network. The pic below these two is concept art of Darth Vader being born as the Emperor looks on. And of course, another pic showing Grievous from different angles. If you think the general doesn't look cool enough (or at all), keep in mind that there are reports that this (SPOILER... Highlight to read.) deadly leader (who is half droid / half alien) of the Separatists' droid army uses four lightsabers simultaneously in the film. Guess how.
UPDATE: Since TheForce.Net didn't provide spoiler warnings for these aweseome artwork, I'll post these drawings here... Go to TheForce.Net to view these in their original size.
Top-left pic: ILM-quality artwork of the Anakin/Obi-Wan lightsaber duel over lava
Middle-left pic: An altered shot from the SW: Insider magazine with General Grievous ready to kick some ass
Bottom-left pic: An awesome drawing of Grievous, also with his lightsabers decked out
Right pic: Presumably the teaser poster for Episode III
Last pic: A cool comic book drawing of Grievous, taken from the Official Site