Have you been following the ROTR threads? The way the Boarding Group process is set up, Guests need to be inside the park and logged onto their phones before park opening to have a good chance at riding it. Due to the huge crowds this is causing, the gates have been opening about an hour before the official park opening time. If you want to be near the front of the queue for another major attraction (SDD, for example), you will need to be at the park well before they open the gates.
Nobody knows for sure, but most are expecting the Boarding Group process to be in effect at least into summer. That's supported by the fact that all DHS EMH's have been moved to the evening until then.
As things are now, if you can handle the walk, that's the best option for getting to DHS super early from the Epcot resorts.