Is a will valid even if I made a quitclaim?

My ex-husband made a will while we were separated naming me as Executrix and also gave me everything in the event of his death. We filed dissolution in July of 2010 and it was finalized in September of 2010. The terms of the dissolution is that was to give him the house (even though I am still listed as an owner because he could not buy me out) and the 93 acres we jointly owned. In the dissolution, I was to prepare a Quitclaim. I have not done that yet but am in the process. My question is, if he gets remarried and I have filed the quitclaim, is the will still valid? If I do file the quitclaim, and upon his death, would I be able petition the Court to give me a portion of all of the properties to sell so I can pay for the house debt? We have 3 children together, the oldest being 21 and the youngest 17 and I want to be able to pay off the mortgage and place the house in their names or sell off the house and property and place in a Trust for the children.