To start, yeah, as of now, I'd say gaming is a male dominated interest. HOWEVER, I believe it has the potential to be a lot more as a medium. Girls playing video games isn't viewed as a "myth" like it used to be. I personally have been seeing all kinds of people describing themselves as "gamers" or even just playing games.
Gaming is mostly dominated because us guys were really the first ones to get at it and stick with it, and ever since, it's had the air of a "boys club". Even if we really do wanna see more women in gaming(Most of us do), it doesn't happen because the stigma's already sort of attached. It's starting to fade more and more though with the presence of female developers and gamers. Hell, even girls I know who AREN'T "gamers" are more willing than ever to at least give it a shot. It's becoming more inclusive as time goes by and I hope we'll see more of that.