Basically, the message that seems to have come from the Church is: Attending church is about worshiping the Lord. We are encouraged to wear our best dress.
But like I said, I didn't actually read the official statement. But that seems to be in line with what I would expect. As an LDS woman, I have been encouraged on several occasions to wear "Sunday appropriate" attire. And though I don't particularly like wearing a dress, I think that dresses/skirts (of appropriate length!!!!) are appropriate attire.
And here is why---
The way you dress, changes the way you feel and act. Don't believe me? Ever gone to a job interview? What did you wear? I'm going to bet it was not the same thing you would wear to the grocery store. I wouldn't. Dressing up for a job interview helps give me confidence--and I believe helps show my potential employer that I am a respectable person worthy of being hired.
If I am in a skirt, I'm going to feel and act differently than if I am in raggy jeans. If I'm in high heels (which I never am) I am going to do different things than if I am in workboots.
A forgotten point may be that MEN are also asked to wear "Sunday appropriate" attire. Living in the west (with a more lax dress code in the work week), I have been in numerous work settings where jeans are acceptable--for men and women. I served my mission in the eastern United States. The dress code at work there seemed much more defined, and jeans seemed much less common. In that setting, it may be harder to see that men are being asked to dress differently than their normal work day. But in the west....lots of men go to work in jeans--and are asked to come to church in dress slacks and a tie--preferably even a suit coat.
Tradition my help define WHAT is considered appropriate Sunday attire, but faith helps me define WHY. We are going to worship a Being we believe to be Holy, Supreme, Omniscient, and in general, infinitely better than we currently are. And to worship such a Being, I would prefer to be at my best self. And I believe that the way I dress influences my ability to reach that best.
Do I think women have to wear a dress to church? No, but do I think they should? Yes.
But hey, go ahead and participate in wear pants to church day....and bring a friend :)
