Motherhood and Media, man.
I think, at the very least the way motherhood is portrayed in the media has evolved since the Leave it to Beaver days. By how much? I'm not sure. Today, however, you see mothers like Lois on Malcolm in the Middle, the only strong woman in a family of 5 boys and one overly sensitive husband, keeping everyone afloat. Despite her reputation for being an unfeeling nazi, and the center of the show revolving around the family's dysfunctionality, it's clear that without Lois, there would be no family at all. And mothers such as Lorelai Gilmore, who raised a brilliant daughter, started her own business, and thrived as a two-component family in small town Connecticut.
Then again, you have mothers like Samantha Newly's mother on the new series, Samantha Who. Her sole existence seems to revolve around finding Samantha a decent husband, convincing her husband to redecorate the house, and hosting luncheons at her house. To me, this seems to be a step backwards, a step back towards the days of mothers entire lives being based in the house. This would be a fine choice, but the mother on this show has very little integrity with which to back up such a decision. Just a "stereotypical housewife".
It seems to me that you see very few stay at home mothers outside of the realm of sitcoms. And within sitcoms, you get the occasional african-american family, or african-american next door neighbors, but overall it seems every sitcom is based around a middle class suburban white family, and their trials and tribulations. Extremely rarely are any issues of sexuality or class dealt with. Race is slightly more common, but even then it is sparse.
I believe that there has certainly been some sort of improvement in the media's portrayal of mothers in and out of the home, but as it seems to be with most of these portrayals, we still have a long ways to go.