I'm happy that he is going to get his GED!
You may want to share my comment with him. My boyfriend was 29 when he went back to school. He chose mechanical engineering, devoted himself heart and soul, earned a 4.0, and was just accepted to one of the top engineering schools in the world, with scholarships and grants that cover 90% of his tuition. Sounds like a success story right? It is in the long run, but in the short term, it has taken a toll on his emotional health and on our relationship.
In order to earn a 4.0 in a tough major, he has to spend almost every waking moment studying. The immense amount of work and reduced quality of life makes him emotionally distant, preoccupied, and sometimes depressed. Thus even when we find a little time together, his mood is rarely lively. We're hoping this changes after he transfers, since a lot of his struggles are related to community college itself and money issues. Oh, money is another thing: he has none. I usually have to pay for both of us to do anything I want to do.
I think we made it through the darkest time, but in a bruised and battered state. Luckily the university he got into is very close to where I live and work, so we have a shot at seeing each other more often. But school is a full time, consuming thing if you are doing it right. I don't think it's worth it to get a degree and take on debt in this economy unless you choose something marketable and are prepared to work very hard to do well in it.
Your husband doesn't necessarily have to work this hard (if he's OK with going to a lower ranked school/program) and it won't necessarily have as extreme of an impact on your dynamic as it had on mine, but you can expect to experience some degree of all of this if he goes back to school.
Was it worth it in my bf's case? Absolutely. My bf was a bartender who despised his thankless, draining, poorly paying career and lack of security, and he's thrilled to have a shot at an intellectually engaging and well paying job in a few years. All the shit was worth it to escape from the hell he saw himself stuck in.
I don't get the impression that your husband sees his life as hell, and without that kind of driving motivation, he may have trouble being dedicated to school.
If your husband is actually happy with his life... can you accept that? The desire to change has to come from within, and right now it seems like it's coming from you.