The site's about page gives the backstory of the marriage from Greg's perspective, and he explains that he has set up the site "to express to the world the love and devotion" he feels for his wife. As I read the long explanation of the series of events that led up to their current situation (on the brink of divorce) and also read the latest posts on the site, I got the impression that Greg's wife has currently cut off communication with him, so the website seems to be functioning as a place for him to express to her the things that he is unable to say in direct communication with her right now.
Part of the purpose of the site is to help Greg figure out what to do to help the situation. He wants to save his marriage, and readers are writing in with ideas and advice for him. There's an ongoing discussion on the comments page of the site where Greg interacts with readers who give him feedback. To be honest, I have to wonder what his wife will think about this conversation, but I imagine he hopes she'll think that he's trying everything and keeping an open mind.
I'm not sure how I would feel to discover that someone had set up a website to troubleshoot difficulties in a relationship with me, but I do understand the feeling of hopelessness and helplessness that comes with loss. As a writer, I especially understand that processing experiences in writing is important when it comes to dealing with difficulties in our lives; Greg can't control what will happen with his wife, but he can freely express his emotions and experiences in writing, and in the end, isn't that one of the main things that blogs are made for?