As a woman, I do wear pants to Church. My husband is a priest, though, so I always wear a skirt for Sunday Divine Liturgy, because that's what the people expect of me in my role. I wear pants, though, to other services quite frequently. I personally have no problem with women wearing pants (neither does my husband, my spiritual father, or most of the priests I know) provided that they are appropriate. It's perfectly fine for a woman to wear a pair of dress slacks for Church or a pant suite. As with any clothing for man or woman, though, modesty is key.
As well, the rules of modesty apply for men just as for women. A man wearing pants that are sagging and bagging, busting slack, whatever you want to call it (wearing them around their thighs instead of their waists) is just as inappropriate as a woman in form-fitted pants, and is just as distracting.
I just say aim for modesty and you won't go wrong. And if someone says something to you about wearing pants, just reply politely and with love, "With all due respect, what I wear to Church is between me and my spiritual father. Though I am so sorry that you were looking at my clothing and not participating in the miraculous service taking place in front of you. You missed a beautiful service." They'll get the picture.