S.,
I think this is perhaps the most difficult issue moms grapple with. There really is no "right" answer that fits everyone's circumstances. I do think it is easy to live a lifestyle that makes us dependent on a second income, when we don't really have to be. But I also know that most of us who aren't earning an income have to live with some financial sacrifices, both in areas of "need" as well as "want." I also think that if you have such strong feelings, you probably will have some regrets down the road that you didn't stay at home at least for awhile. And husbands usually have no real idea of the other sacrifices that are made by the moms who do work outside the home! It will get harder, instead of easier. And the burdens generally fall on the mom.
That being said, why not try to have the best of both worlds in some way? Work for another half year or two, but begin living only on your husband's income. Start saving every bit of money you bring in. This will give you and hubby time to adapt to the one income lifestyle; it will give a good reserve for future issues; and if the economy stays bad for long, it will hopefully keep you employed when you most need it. After you've reached a reasonable savings amount, give notice, stay home, and enjoy the time with your child. It truly will give you more than you could ever imagine! And, personally, since we're the ones who conceive, carry the pregnancy, deliver the child, and have permanently changed bodies as a result, you deserve this and your husband needs to acknowledge that (IMO). I think men don't really appreciate that whole dynamic nearly enough!
Good luck sorting through all the pros and cons. I hope you will find a way to stay at home, even if briefly, but I completely support any woman's decision - or need - to continue working.
(and I don't want to sound like a male basher, but I think it's also possible for the men to work a second job, even if part-time, to support their wife in staying home with their children. And if you do stay at home with your child at some point, I would encourage you to really consider in advance some good boundaries with your hubby about handling the income!)