Unfortunately, we won't ever get anything close to 1000' in downtown as the highest limits in downtown are along 7th Ave where it can go up to about 650'.
Anything taller than that would have to go up in Midtown unless Phoenix does a major overhaul of it's development/height code north of Fillmore and I don't think there is any push for that barring some major office space needed in downtown for a headquarters or something...and we all know how much office space is needed in downtown
Phoenix is forever doomed to be short...at least in my lifetime.