I can't help but think that with the advances in concrete structural production methods that this can't be done for a proportionately lower amount. That is, less than the adjusted current $5m per mile as some have estimated. Seems that the cost should be quite a bit less. I too would be interested in seeing the cost analysis for this.
When the original monorail was constructed, the beams were made and shipped by train from Washington state. At todays rates, that's a lot of money. They could be produced locally using a slip cast method, and should Disney insist on keeping the same arched underside beam design, the casting could be done upside down (flat side down) to allow for a single machine to quickly cast around the rebar structure and allow for the arch. Even the pillars can be pre-cast in molds at a backstage area and bolted in place. Additional advances in conrete blends and rebar design may even allow for longer distances requiring fewre pillars and lower ground prep & base costs. Modern electrical distribution systems should provide some enhancement to the equation, potentially lowering operating costs on a new line verse the old line(s).
I don't see why the same train body design couldn't be implemented again as Bombardier already has the molds for the composite body production. This should radically reduce implementation costs as no new design is required. Additionally, Disney just upgraded the control system no long ago, so again, no new design required.
Oh well, it's all Fantasy in the Sky anyway, right?