I would supose it's a lil more like
10% porn
60% bitching
29.8% emo live journals
.2% every thing else
You forgot marketing.
Setting can be adapted to any system - some better than others. If you use the system included in the game, you are saving yourself a lot of work and headaches as a GM, but it's your game, do what you want.
I made a pretty good frame for running a dresden game in White Wolf's Scion system. Never did get a group to play it though, thank to the tragic end of college and this stupid Real world everyone keeps going on about.