Amazon.ca is now showing Phoenix Vol. 10 as being solicited for March 2007.
No look at the cover yet, but the description shows the story will indeed be "Sun". After flipping through the Japanese version, I'm really excited about this story.
Sun:
In A.D. 663 a soldier named Harima is punished by being given the visage of a wolf. Rescued by a mysterious old woman, he is tormented by nightmares and gradually senses the spirit of Bando Suguru, a 21st century agent who fights on behalf of banished humans.
Sun is the longest chapter in the Phoenix series, and its structure is threefold. Harima's story in 7th century Japan interweaves with that taking place in the 21st century, while another tale of a spiritual battle bridges both past and future.