Jeff. M. passed on this good summary of the state of women in combat in the U.S. military. Here's an excerpt:
Opposition to women being assigned to combat units comes primarily from those serving in them. While 74% of the general public would support changing the policy, the characteristic attitude among infantrymen... on the subject is that “‘integration’ erodes combat effectiveness–lowering behavioral and proficiency expectations and riddling the force with time-consuming misconduct issues.”
Physical standards currently are gender specific in the military. The Army physical fitness test requires the same number of sit ups for men and women, but women are given more lenient standards for push ups and the timed run. The Marine Corps physical fitness test allows women to hang from a bar instead of doing pull ups. Where combat training has been opened to women (both in other countries, and in recent U.S. Marine Corps efforts), few women apply, and those that do suffer much higher injury and attrition rates.
Both the Army and, most aggressively, the Marine Corps are currently developing gender-neutral occupational standards for infantry...
...the Chairman of the Joint Chiefs of Staff has (suggested) he may intervene to reduce physical standards. General Martin Dempsey has said that “if we do decide that a particular standard is so high that a woman couldn’t make it, the burden is now on the service to come back and explain to the secretary: Why is it that high? Does it really have to be that high?”