I talked about this in the thread over in the lit forum.
1) Is there a market? Decades of getting fanfic for free and suddenly fans are going to pay for it?
2) Potential to screw over popular tie-in authors or at least put them in a position to cut into their paychecks. You (fanfic writer) work for free and the studio gets part of your sell; versus a pro who gets and advance and--once they earn out the advance--royalties.
3) What happens if a studio pulls out of the program? Are you fucked? They pull out, does that mean all your work is pulled down, you don't get paid?
4) Fanfic sites? How screwed are they going to be now?
It's an interesting change, but I'm pretty cautious about what this means to the future.