What does it mean when a guy discusses marriage with you?

[Amanda]

My ex is in the army. We knew each other for a two months before he left. Before he left we discussed getting married in the future, but then things went sour. We had an open relationship it didn't work, he came back in April and before he came back we had talked and both agreed that we still love each other and when he comes home we can get back together. I told him I would wait for him till he comes home in September after we mutually agreed getting into a relationship again while he is away isn't good. The other night he brought up the topic of marriage again and he said...(sigh)...maybe when i get home we'll get married and move in a house and have a story book family. Then he and I logically talked about like me graduating from college and him buying a house then we would get married and he would use the GI bill to go to college and continue to do his drills and come home homework and time with me. We would wait at least 1 or 2 years to have children after we were married. Is a guy bringing up marriage a serious topic these days because there is no doubt I can see a bright future with him.