You guys are going to make us pay another $20 for the Linux version?
Well I hope it plays as well.
I think it is an excellent decision to build for Linux. Penumbra hasn't been getting the attention it deserves for being as good as it is (I feel its a lot better than Silent Hill 2). There aren't a whole lot of games for Linux and fewer have the latest generation graphics (Doom 3ish). This game has GOT to get the attention of the Linux gaming community just because its one of the few. Is there a Linux gaming community? There are certainly a lot of Windows gamers that are tired of Windows.
I just switched from Windows XP to Ubuntu 7.04 after I tried Ubuntu and got hooked. (I love the permissions in Linux. And Ubuntu was easier to get up and running than Windows XP). Yes, I have a dual-boot system and I boot into Windows when I need to run whatever but I *dislike* booting into Windows. I'm certainly not going to upgrade to Vista - its definitely a liability when it comes to optimum game performance.
Hopefully more game developers will go your route and port their games to Linux.