I too am a Linux user, I can agree to per-order but only if Linux support is guaranteed. I see you say "delayed but not dead", makes me hesitant. Can the actual Game Developer make a statement that Linux support is guaranteed?
The game looks pretty awesome!
On the Feb 14 QA, Mitch, Jordan, and Mike clearly said it was going to be 2-3 months after launch at the same time as localization.