Looks like there IS a huge demand for a Linux version; just take a look at the huge amount of people who signed up to the forums, and only made one post just to say that they want a Linux version too! Well I'd have to agree. Right now I use windows on my desktop for gaming and Linux on my laptop, but I'd prefer to have both computers running Linux. I used to use Linux for gaming, but after a while I got sick of wondering "is this game going to work or not" and putting dozens of hours into fiddling with wine and cedega. If Runic were to put out a Linux version of their game, it would enable people like me to use the OS of their choice to play the games that they love.
However, given the choice, I think most people would rather have their own OS and no game rather than switch to windows like I have just to play a couple games. Releasing a Linux version is a smart thing to do that would capture this new market, as well as generate the undying love and affection of fans such as myself. We Linux users are notoriously loyal to companies that support our OS of choice, and having such an extremely loyal fanbase for a company is something that is extremely invaluable.
Do the smart thing Runic, and release a Linux version, for the good of your users and potential users, as well as for the good of the community and Runic Games itself.
Torchlight player, community member, and Linux user.