There were four volumes put out by Dark Horse, and the detail, environments, and personality of the main characters were just astounding. The preview that just came out indicates that they have captured the vastness of detail from the comic, as well as an intensity and extreme pacing that fits.
Here's the official Movie Site. Unfortunately its mostly in japanese, but there is enough english to do basic navigation and get to the trailers. Looks like release is April 17th.
I am so jealous.
A brief history of Appleseed.