The Cowboys finally went ahead and hired Chris Palmer. From ESPN:
The exact title for Palmer, who agreed to a two-year contract, is unknown. Ostensibly, he replaces assistant head coach/passing game coordinator Sean Payton, who left Dallas two weeks ago to become the New Orleans Saints head coach. It is expected that Palmer will work with the Dallas quarterbacks and have major input into the passing game.
Dallas is not expected to have an assistant with the title of offensive coordinator.