Should my stepson live with us if his stepfather is deployed?

My husband has a son (8 yrs old) who currently lives with his mother and step father. His step father is in the military and they were just stationed in Hawaii. We live in Ohio, which means visits with him will be very limited. His step dad is now being deployed to Iraq. We feel the only reason my husbands ex-wife and the child would stay in Hawaii is because she gets free housing. Her husband isn't even going to be there. The ex-wife and child's ENTIRE family is here. Should we seek custody of the child? She is unwilling to come back home until her husband returns, even though we feel this would be best for the child so he can have the needed relationship with not only his real father (my husband), but also his extended family.