I'm curious to see if they can or will try to charge DVC members a resort fee. It would be hard to do. The maintenance fees already have a line item charge for things like transportation, entertainment and common areas (pool, lobby, etc). Maybe the extra magic hours, DME and advance FP reservations could be rolled out as the reason for the charge, but it would be a tough sell. I'm not even sure if it's legal based on timeshare laws.
As far as hotel guests go, most of the resort fees I've seen in places like Vegas, Hawaii and the rest of Orlando cover very basic services like fitness centers, WiFi, local phone calls and some even list the pool as an amenity. I can't say whether these resorts previously charged a separate charge for these things as you used them, but the trend is to list a bunch of stuff to justify the fee. I have seen some list parking as well. I don't see Disney offering a whole lot more to justify the fees. Possibly something trivial like an upgrade to the coffee like you said but I wouldn't hold my breathe waiting for a big increase in amenities.