The Boston Globe has a great, fairly in-depth piece today on the declining interest of women in computer science. Reporter Marcella Bobardieri writes:

Born in contemporary times, free of the male-dominated legacy common to other sciences and engineering, computer science could have become a model for gender equality. In the early 1980s, it had one of the highest proportions of female undergraduates in science and engineering. And yet with remarkable speed, it has become one of the least gender-balanced fields in American society.
…
The percentage of women studying physics, already low, dropped dramatically and stayed in the single digits for decades. Eventually the physics bubble burst for men as well, and today a high percentage of the country’s physicists are foreign-born.
Some computer scientists fear that they may be going in the same direction. They view the dearth of women as symptomatic of a larger failure in their field, which has recently become less attractive to promising young men, as well. Women are ”the canaries in the mine,” said Harvard computer science professor Barbara J. Grosz.
In the wake of the dot-com bust, the number of new computer science majors in 2004 was 40 percent lower than in 2000, according to the Computing Research Association. The field has seen ups and downs before, and some think the numbers for men will soon improve at least a bit. But the percentage of undergraduate majors who are female has barely budged in a dozen years.
The shortage of new computer scientists threatens American leadership in technological innovation just as countries such as China and India are gearing up for the kind of competition the United States has never before faced.

Read the whole thing (also mentions the National Center for Women and Information Technology).