Let's revisit this questions of equal pay after a couple of years. Right now, Serena and Maria sell out the stadium when they play. Other WTA players (i.e., Bouchard, Azarenka, Keys, Bencic) have their following and it is growing. It depends on the future players generating and maintain interest in WTA tennis. The same goes with the men. What will happen after Fed, Rafa, Novak and Murray retire? You can make the argument that the ATP will not generating enough interest to support the pay.
I think it is silly to make it men vs. women with pay. Women earned equal pay because of the interest they were able to draw to the sport. I believe they work hard with training, playing, promoting and marketing. We all have our opinion, but the WTA rightly won the battle to earn equal pay because of how they transformed the sport.