Regarding Rock Band and the genre it occupies it will soon disappear into the background as developers exhaust the music libraries their games are built on, eventually all the classics will dry up and people will realize how much money they invested and become disillusioned to the whole affair.
Before even getting undresses of feeding their children (husbands included) their tuning the tele to their favorite program; I think it would have been a little more accurate to say that after a long day most women prefer to come home to a passive activity like television rather than an active one like video games.
If these companies want to gather a female audience then they need to tap into the interests that women have, to expect them to be interested in the same media that men are interested in is quite ridiculous.