I'd like to join this thread now, though I won't have our baby until late March/early April. I am deeply, deeply committed to having an equal parenting/equal partnership relationship with my husband of almost 10 years. I know it will be a negotiation, and actually I use the word "equitable" because I know "equal" is a tricky word that a lot of people dance around. I don't think partners are "opposites," but neither are they really "equal" in a quantifiable way, especially when it comes to men and women in heterosexual diads (which is what my experience is in, but of course not the only sort of relationship out there). Based on my personal experience and studies, I'm so convinced that neither men nor women are inferior, superior, or inherently the "other." This includes recognizing that while the role of a "mother" who is a woman can be different than a man who is a "father," "mothers" are not more valuable than "fathers" to babies -- and when you talk about roles and stereotypes that have been assigned to genders, these need to be flexible and inclusive.
The bottom line is that I want both my husband and me to feel as fulfilled and satisfied as possible -- in parenting, in ourselves as individuals, and in our relationship to each other. It's going to take a LOT of work. We have very different jobs, hobbies, social needs, physical needs, etc. But we're really trying to work it out. And I know things will change and develop over time, as we figure out what's right for us.
My husband currently works from home as a freelance artist and designer (and has for about 6 years). His income and hours change constantly. I work 30-35 hours a week outside the home at a low-paying (for NYC) job, and the health insurance we enjoy comes from my employment. My schedule is a little flexible. I don't think either of us will be able to be a SAH parent and keep paying our rent, nor does either one of us want to stay at home (at this point; I know that may change after the baby is born). We have a goal to share cleaning and household upkeep duties equally and already do pretty well at that. Our current (read: incredibly loose and up in the air) plan is to each work 4 days a week, and balance our 4 total days off (3 for each of us, 2 of which would be the weekend days, which we'd share) with some sort of nanny share or babysitting coop situation (infant day cares in NYC are few and expensive).
In reply to the previous post, I think biology is a factor in human development (and parenting), but I do NOT think that it is such a strong factor that it outweighs sociological ("nurture," as opposed to "nature") factors. Also, I think a lot of things people THINK "are biological" are actually socialized so deeply that we have become lazy and mistaken about them, unthinkingly reinforcing stereotypes we may think are natural.