I'm sure they have thought about this in in the past. It would work similar to how Universal's Express for on-site guests works. Obviously, they'd have to charge more as there are more guests at Disney parks, but I think it's something they should look into. Use it as an add on to the MYW ticket, the same way they have the park hopper and no expiration as add ons. They could base it on length of stay, or just one flat fee per ticket. Charge say $200 per ticket. As a family of 5, I think it'd be well worth $1,000 to not wait in lines.