DH is science based. He is not an atheist, he simply believes that he is not the one with the answers. He would lean towards atheism, though he is accepting of others and their beliefs.
We were both christened, though neither of us find it necessary for our children. Neither of us see the point in christenings, baptisms, or naming days at all. My kids will make their choices when they want to. I find non-religious people baptising their kids incredibly hypocritical actually. And I don't understand naming days AT ALL. Your child already has a name. Don't get it?
Depending on your DH's denomination, some churches offer a "dedication" which is a welcoming into the community. Far less official than a baptism. Also, pp's suggestion of some form of party with a minister saying a special prayer could be a nice compromise too.