Child support expectation

My husband now makes around 180,000. He is accepted job in Washington state without letting me know. We have discussed the position, but since telling him I want a divorce. He has accepted the position without my knowledge today. His income will be projected around 300,000. I cannot and will not move from my family and my home. He has threatened me with taking one child- and one child only with him to Washington. We have lived here in NC for 7 years and have a home. We have not met with anyone in regards to this since I just told him Wednesday 8/27/08 that I wanted a divorce. He admitted what a terrible father and husband he has been over the past 5 years in an e mail to me. He promised me the world and that he would change. I am through giving him chances and want to move forward with my seperation and divorce.
What are my rights and what might I expect as far as child custody if he does move to Washington?

Thank you so much for any help and input