The image, available for sale as a lithograph directly from Dark Horse, depicts the Persian King and reveals the logo for the series which, if the film adaptation follows 300‘s lead, will presumably match that of the upcoming film version.
The product description includes the following description of the series:
"Xerxes rose to power in fifth-century-BC Persia and became known as ‘The King of Kings,’ eventually raising and leading a massive army intent on ruthlessly destroying the hated Greeks who killed his father. Xerxes seeks nothing less than to become a god himself — and achieves his wish!"
The print features art by Frank Miller and coloring by Dave Stewart.
UPDATE: Frank Miller spoke today with the Los Angeles Times regarding the comic book project, revealing a number of specific plot details.
"The time frame begins 10 years before 300," said Miller, "and the story starts with the Battle of Marathon, which was killer to draw, by the way, even if it was a lot of work. The lead character is Themistocles, who became warlord of Greece and built their navy. The story is very different than 300 in that it involves Xerxes’ search for godhood. The existence of gods are presupposed in this story and the idea is that he’s well on his way to godhood by the end of the story."
Describing Themistocles as "the complete opposite of Leonidas," Miller does promise that the 300 character will make a cameo. While that doesn’t guarantee Gerard Butler cameoing in the eventual film version, it does make it likely, as does an appearance by Andrew Tiernan as Ephialtes, the deformed Spartan traitor who Miller promises also places a role in the new story.
"There’s an extended scene set in Persepolis," adds Miller, "for instance, where he takes power and there are several scenes where he is going through his transitions and he’s shown speaking to his mother and his wife… The new tale climaxes with a massive naval confrontation that is so dense that it is fought like a land war and it ends on the same day as the events of 300."