Sometimes stuff happens between friends, but most of the time it doesn't. Most of the time when it happens alcohol is a contributing factor, lol. That can really lead to a big mess. Dating your friends isn't that great of an idea because you know too much about them. It's so easy to slip up and hurt a girlfriend who used to be your friend because they know you know so much about them, and it makes them self conscious.
The true asset, from a dating point of view, that having friends of the female sex is finding dates. If you're their friend, they think you are sooooooo sweet. They'll work the inside angle for you 9 of 10 times.
Oh, and by the way. Not making the move can lead to the friends thing or nothing. If you don't make a move, they don't think you're interested.