The Artificer is available for playtesting for the past few days in Dragon before it makes its appearance in the Eberron Campaign Setting. You can download the playtest notes here.
According to the WoTC, once you are done reviewing it and have any comments, you can send them to firstname.lastname@example.org. You have the chance to change the fate of one of Eberron's loved classes.
Artificers treat mastery of magic like a technical skill. They see a pattern in energy and matter, and they develop an understanding of how to manipulate the flow of arcane energy in and around material objects and creatures. Artificers learn to channel magic into items by using complex chains of sigils and diagrams or by using magical materials. With their skills, they can assemble the perfect magical object for any situation.
Discussions are under way already here. This will be an interesting read for awhile.