Yeah...
Thats been my feeling from documentaries watched and articles that I have read.
Pixar use Linux on their render farm as far as I can tell, I mean its faster and more stable when its given a lot of data to process.
So to answer the question lol.
Linux is used, but not extensivly as a front end/desktop system for asset creation. You will more than likely see it used for asset storage, file management and the heavier back end systems, like render farms.
Chris (formerly R@nSiD)
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Winner SM VFX Challenge 1

3rd Place SM SteamPunk Challenge (May 2007)