I would also add (perhaps per workstation - though the walls will be getting pretty full): compressed air and natural gas (might as well have the capability for chemical lab work, as well as light metal soldering and glass blowing).
Looks great - and I'm pretty envious (two things I wish I had - more space, and air conditioning).
Oh - one more thing: Add one or two circuits for dedicated arc welding use (maybe on the outside of the shop).