Women's soccer can become very successful/popular at an international and club level (never comparatively for male fans, but more so for female ones of men's soccer), it just needs to be marketed properly, and given time to build and improve.
Tighter shorts would get a few men to flip channel's once in awhile, but it wouldn't do Carlos*all for the game in an overall standpoint.
The women's game is about 100 years behind the men's, in terms of tradition, history, and the foundation for developing players. Give the women's game some time, along with the opportunities and dreams of playing at a high level, and the game will come along -- better players, better teams, more fans, more money, even better players, etc..
Yes, women's soccer will not be able to offer the strength, speed, and power of the athletes on display in men's soccer; however, there's no reason why a female player can't be just as skilled, just as gifted, as a male player. As the game approaches that point (like golf has in recent times, or tennis), there will be no trouble keeping leagues like the WUSA alive.