I would expect Disney to roll out a paid FP system and that it will not be cheap. They need to price it high enough so that too many people don't buy it. If they have too many people buying it then the value would not be there. Why spend money and you still have long waits? Therefore, the standby lines should move along nicely.
I could also see them making it an option to Deluxe hotels/
DVC. Just like you could buy extra FP if you stayed on club level. My reasoning is what would you choose 1) a cheaper room at like POP and use your money to buy FP access or 2) expensive room and no FP. (Assuming that your budget doesn't allow both). Disney could see a number of people downgrading their resort hotel to save $ for FP.
This could give us a choice. I would not buy a FP for EPCOT but I would buy for HS if it means I can get on ROTR! Choice is fine.
Will be interesting to see how this evolves.