If this project is completed it will prove that anything that has been built by man can be rebuilt by man - all it takes is enough money. What's interesting to me is that they are building the easy, low cost flashy stuff first. The sheet metal cab and nose are pretty straightforward and easy to build but are really flashy and something they can show off. If the organization folds the parts can be sold off to become some decoration in a building somewhere. Casting the drivers is a little trickier but still pretty straightforward and something they could sell for decorations. It's when they get to the boring big things like starting to build the boiler, frame with the running gear and tender then I will believe this is really going to happen. For those who are involved in it I hope it gets built and their efforts pay off. But being a west coast SP fan I won't get too excited about it.
The positive outcome of this project would be seeing what techniques and resources they use for the project. People doing other restorations may be able to leverage the info to help with their projects.