Preview video looks good - Love the fact that you have to build stuff from ground up instead of magically appearing.
Couple of thoughts:
1. Multiple floors or just one floor layout?
2. Are the builders at risk while walking around the prison building stuff? Can't imagine it being very safe having lots of (power)tools in a prison complex. Will the builders need security guards and "deadzones" to keep the inmates at bay?
3. Sandbox or storydriven? Will we have scenarios such as "endless mode" where prisoners just pile up endlessly?
4. Defenses? Will inmates try and break free? Do you have to think about big walls, barbwire fences and landmines?
I am stoked - It isn't Subversion (whose graphical design I absolutely adore), but I love building games like Dwarf Fortress and Dungeon Keeper (Anything Bullfrog/Sierra really) games.
On a more serious note - preorders? Any timeframe for these, or plans at all? I'd love to pledge a purchase even if the game takes another year to complete.