My biggest concern is the Standby Pass. According to the DLP site, "The Standby Pass service will only be activated during certain periods of the day in order to help reduce wait times for certain attractions. You can still queue for these attractions without a Standby Pass at the beginning and at the end of the day (times may vary)."
To me that sounds like such a program could end up meaning for me to ride 7DMT I'd have to a) Rope Drop (standby line opens briefly until it hits their limit, possibly 60 minutes), b) be in the park to get a "limited quantity" standby pass before they are all taken, with a reserve time which could be hours later, as shown in the promo photo on the DLP site - and locking me out of another standby pass during that time, or c) wait until the end of the day when the standby line opens again (likely right before park closing). And what about park hopping? If you hop to a park at 2:00, do you really think there will be any time slots available for the most popular rides there? Oh that's right, there will be, at $10-$18 a seat....
Personally I'm not against the paid fast pass thing. But I am not a fan of Disney straight up denying access to what may be ALL popular rides at ALL parks for ALL times other than rope drop and closing unless you pay $10-$18 a person.
I realize this might be an extreme example (and maybe playing a little devil's advocate), but with the parks becoming more and more busy, how can this not be at least a possible scenario? Think long lines are bad now? Wait until your kids are complaining they can't get on any of the "good rides" because the Standby Passes are gone for the next 8 hours as they are forced to go on Small World or the flying carpets for the 5th time because they can't go stand in line for anything else. Disney maybe hoping that motivates parents to shell out the $$ so they don't end up feeling like the trip was a waste?