lovemykids got to it before me... I don't think it should be 50/50. It should be 100/100.
I second that specialmom..LOL! I tend to do more around the house because my husband does what I call a "half a$$" job and I like things a certain way. Plus, he works nights and I work days in order to not have to put our kids in daycare so he doesn't get much sleep as I do. When he has days off, he helps around the house, but the majority falls on me. I prefer it that way!
I think what makes for a happy marriage in terms of splitting of responsibility is whatever satisfies both parties. The number may be different in each unique couple.
I definitely do more around the house than my husband . . .but that is for two reasons. First, I'm a stay at home mom at this time so I feel like part of the deal with that is that I will take care of more things at home. My husband, obviously, brings home the pay check. I help out by being careful with what I spend but he shoulders the financial burden of our life as a family. The second reason I do more around the house is I'm a bit of a control freak. I like my kitchen a certain way . . . and might be pickier than I should be about how he does things when entering my domain. So, I tend to just do it myself. Out of choice.
But if one person in a partnership feels like the unfairly take on more responsibility, that is a point in which communication and compromise is a must.
In terms of respect, we are 50/50 though!