I realize every relationship/business is different, but how is that working out - both in the relationship and in the business (if you don't mind sharing)?
Generally, investors are wary of married couples, in that they've been burned before. So we need to be very cognizant of the way we act around each other to ensure they get the most positive impression. If you read accounts of the flickr cofounders, you'll also get anecdotal evidence (that I've never experienced) that some investors are assholes and don't take women seriously.
We have complementing skillsets, which is perfect on the work side of it.
On the relationship side of it, I have no idea how people do startups that have significant others _not_ involved. Not only do we spend the vast majority of our time on the project, but we talk about it when we aren't working on it. How could an uninvolved party tolerate that?
Michael and Xochi Birch are part of the founding team behind Bebo.com, which seems to have worked out rather well for them financially. I'm sure founding a company adds some extra stress to any relationship but you can certainly take proactive steps to assuage that.
One blogger (relatively well known) but I can't remember which (sorry!) blogged about how he and his wife set aside a monthly date to re-connect. They go out to dinner, and exchange gifts (big or small.) There was quite a bit more detail than that and I think it's a good ready for any of today's super-busy couples. After 30 minutes of searching around I just haven't found the link. Maybe someone else here remembers the piece (or wrote it?)
I don't consider my wife a co-founder, but she is definitely a part of my team if nothing more than being in the cheerleading section.
She was not as fully committed as myself and she smartly vetoed the mortgaging of our home to get the project done, but once she caught my vision she became as dedicated as me to seeing the project become a success.
I had her read "Internet Riches" to get her non-techy mind into the mode. It was after she read that book that she became fully committed and supportive.
I guess I can't really classify her anymore as "not_involved", and that's good for both of us.