I think it's a bad idea... and it's going to lead to unnecessary deaths and costs. But, then again, when has that ever been a problem for our government...? Especially when political correctness was in play.
Even if women can meet the same requirements as their male counterparts on the front lines, and most of them cannot, it brings about all kinds of awkward and potentially hazardous situations. It needlessly complicates things, too.
Rolling towards Iraq, some combat units were crammed shoulder to shoulder in armored personnel carriers for days with very few stops. Need to defecate while on the move? You have to use a bag and do it in front of everyone else in the back of the apc while it's rolling through the desert. How is a woman going to feel about dumping in a bag in front of a bunch of men, all crammed into the back of an apc? How are the men going to feel about it? Stopping and unloading, just so someone can save their dignity, can potentially cost lives when every minute counts during an assault deep into the heart of a hostile nation.
After long patrols, before the infrastructure was in place to accommodate the soldiers, the Marines would sometimes just line up, undress and get hosed down, together. Is a woman going to stand in line, naked, like the rest of them? Separate bathing times or facilities is going to cost money or time (or both) during those first few weeks of a hostile action.
Like it or not, guys like women. They like looking at them, talking about them, etc. Often, this strays into more "crude" areas. It's natural... it's why pin-ups were so popular in the past, it's one of the motivating factors for units full of men. Are women going to be ok with this kind of thing? I would hope so... but there is bound to be that 5% that think such overt sexualization of women is unacceptable or uncomfortable.
Of course, there's also the natural, ingrained instinct of most men to protect women. It's hard-wired into our genes. Military training and discipline can certainly mitigate this to a certain extent... but you can't just undo thousands upon thousands of years of instinct. This could lead to some dangerous risk taking.
Finally, what about the shitstorm that is bound to erupt when a female soldiers is captured, raped, tortured, beheaded, etc...? You know the media is going to show that in a different light... which is likely to place more stress than usual on the military.
I just think this is a bad idea, and will lead to innumerable problems.