I was looking at the Facebook comments of this and found quite a few Disney Moms pointing out something I had no idea about: Uber charges an extra $10 for a car that includes a car seat, but Minnie-Vans have them included in the price. So for families with little ones, this is about the same price as an Uber, if not cheaper. It's also great for people with disabilities who have difficulty taking public transportation.
Also, a quote from the Disney Park Blog update:
"Starting later this month, guests at Disney’s Boardwalk Resort and Disney’s Yacht & Beach Club Resorts will be able to arrange their own private Disney vehicle right from their smartphone. It’ll be simple to do. Just arrange a Minnie vehicle and a Disney cast member will arrive and drive you anywhere you wish at the Resort in a magical way that only Disney can do."
UPDATE: New Minnie Vehicle Service Begins In July at Walt Disney World Resort | Disney Parks Blog