Whether he says he wants to stay separate or get back together after the two weeks, you should try to get him to agree to go to Retrouvaille with you. That is the marital retreat that PonyGirl did with her H a month ago. She and I have both done it, with different results, but we both highly recommend it.
Look at the retrouvaille website, http://www.retrouvaille.org to see what it is about, and find dates and locations for a weekend near you. This is the single most effective thing you can do to repair your relationship. I know you will need a sitter for the weekend, but it is worth is. Maybe your son could spend the weekend at at friend's house.