Of course, it all depends what you're movie is. I don't doubt it for one minute that some studios are switching platforms. Maya perfers Mac OS X. If you want a job in the industry, you'll need to be Maya/ Mac OS X savvy. It also never hurts to know other OSs as well. (Shows versatility)
I don't think Maya is available on Linux. Maya is considered The animation tool. It really is pretty cool. I have played with it. Lucas and Co use it (as well of some of their own proprietary stuff). Lord of the rings had many, many scenes using Maya. Info here
Of course, it all depends what you're movie is. I don't doubt it for one minute that some studios are switching platforms. Maya perfers Mac OS X. If you want a job in the industry, you'll need to be Maya/ Mac OS X savvy. It also never hurts to know other OSs as well. (Shows versatility)