The short answer is yes, women do more housework than men, but it's shifting in the direction of more equal distribution of labor. There's a fantastic and well-referenced summary of current understanding on Po Bronson's site.
According to The Journal of Marriage and Family in 2002, women do more housework than men, but not all of it by any means. (See this graph of the results by country.)
Much more detail can be found in this article from the Marriage and Family Encyclopedia, which suggests that since the first major studies in the 1970s, men have been taking on more of the housework, although women still do more than men in most households.
According to an article from 2000:
Household work continues to be divided
according to gender, with women
performing the vast majority of the
repetitive indoor housework tasks and
men performing occasional outdoor
Taken from: Coltrane, S. (2000). "Research
on Household Labor: Modeling and
Measuring the Social Embeddedness of
Routine Family Work." Journal of
Marriage and the Family 62:1208–1233.
Similar information can be found from Philip N. Cohen, Suzanne M. Bianchi et al., Crompton Rosemary and Lyonette Clare, and many others.