I had heard that there were going to be no changes made to the ride vehicles, other than adding a touch screen to the car. That seems to be what people who have ridden are reporting on threads on the Theme Parks Board. A number had mentioned that the same old cars were used, just 'updating' by adding the touchscreen. I wondered if the touchscreen would make it even harder to get in, but I haven't seen any pictures yet.
When we were at WDW in October, we did look at the old wheelchair waiting area and that had not really been changed. So, the 'where you board' at least looks the same.