Well, there are definetly natural 'talkers' and then 'quiet' people. A quiet person can do things to make himself more talkative, but usually his quietness is a pretty hardwired part of his personality, so he's never going to be quite the socialite that the natural talker is.
Now, there is definetly a level of quietness you can reach that will prevent your success from women (when you just can't talk AT ALL), and if you're that quiet you need to do some work, get over whatever social anxiety problems you have, etc.
But if you're only 'somewhat' quiet (you can carry a conversation if you need to) then you can use it to your advantage. Girls, I believe, could really care less about how much you talk, EXCEPT that talking gives off the perception of being socially important and often, confident- two big things girls look for. If you can show a girl you are those things, WITHOUT chattering constantly, you'll be just as good, maybe even BETTER, in her eyes.
Women are known to have something for the 'strong, silent' type, like a cowboy or something. If you ever watch westerns, you don't see John Wayne or Clint Eastwood being the big talker. But other men respect them, and they clearly have confidence, which women can tell from the way they carry themselves, so women are attracted to them.
Plus, we all know how women love to talk. From all that I can tell, when it comes to talking, women don't care so much for the man talking but for how well he can both listen to her and lead the conversation with relevant questions/statements that allow her to open up.
I actually kind of see guys that talk way too much as a little effiminate. It's wierd when you have to tell a guy he's being annoying from talking too much. I don't know if this femininity is something women pick up on or not, but I suspect they might, and at the very least, guys will have a harder time respecting you as a man if you talk as much as a chick.
Sometimes, being quiet (if it's not done in a way that suggests insecurity) can be a little intimidating to other people, both men and women. It's almost as if you have a slight air of being 'better' then them, and this can translate into your having confidence in women's eyes (though I'm not saying this is always a good idea). Plus the suprise they show when this guy has hasn't said much the whole night starts chatting them up is a big plus.
So in conclusion, the percieved superiority of 'talkers' only exists b/c the talkers are the ones who, well, talk to women. If a quieter guy doesn't talk to her, she can't really choose him. It's not really a matter of a women actually preffering talkers over quiet guys. In fact, women might actually prefer a quieter guy if they had a choice. But it would have to be the right kind of quieter guy.
-E-Z