What alot of people here seem to be forgetting is Pathfinder Society play.
The argument that you don't have to allow it in you homebrew campaign flies out the window. No one can say I don't like the idea of forcefields in PFS, if it's legal for play you will be FORCED to accept it. Which for many will likely kill the experience.
There are to ways to handle this:
1. Either the expanded rules will be available for a year and then no longer legal for play which will make all the people mad who made a character and now have to abandon or re-write to fit in with a histrocal fantasy setting once more.
2. The expanded rules will largely be legal for play from now on. This forces people who wish to play PFS organized play as it was before the module to accept that they will be wandering into an ancient dungeon with a cybernetic half-orc with a light sabre and gatlin gun, thereby ruining the experience for them.
As someone who just recntly got into pathfinder/PFS after quite a long absence from fantasy RPG, I think it kind of sucks. I have barely gotten a chance to play a fantasy character and enjoy the setting and now there are plasma weapons. If I wanted plasma weapons I would have looked for a Sci-Fi RPG.
If paizo goes with option one detailed above this will mean I probably won't play for a year, and hopefully I will come back after such time.
If they go with option two detailed above it might mean the death of my invovlement with PFS. I just don't want to run through a scenario with next to a guy with a plasma rifle when I am playing a barbarian. So i get shot with a laser and my DR saves some of it? It just doesn't fit.
