I know how long people have been trying to make this work forever, but I feel I'm a bit close after playing with it for a while.
This solution uses Wine, FirefoxPortable (so it's self contained and not relying on registered dll's a lot) and using instructions found at the following link for getting silverlight installed into the portable app: http://portableapps.com/node/14188
I think it's REALLY close to working. I can open netflix, and hit the play button, at what point it goes through a "please wait while this installs" then finishes, giving me a screen with the netflix streaming controls, and sits at a screen saying "Thanks for installing, once installation is complete please restart your browser to watch this movie." If I restart the browser, it does it again.
I think it might be more of a firefox configuration, something to tell it that silverlight is there instead of trying to re-install it. It's registering as an installed plugin but silverlight test sites work albeit very slowly and with mixed results.
I'm not having any more luck, but it seemed like a method with promise i haven't seen tried before. Here's a whole package with my experiment, all set up: http://www.surfrock66.com/FirefoxPortable.tar.gz feel free to download it and try to make it work for yourself.