I picked up a leaflet at hotel reception which outlined which rides were open am and pm EMH and dates. It was only for 2 weeks but I assume the rides will be similar on other dates as well. It is very similar to last years magical hours.
am:
Castle
Pinocchio
Carrousel
Peter Pan
Dumbo
Tea Cups
Buzz
Orbitron
Space mountain
(Also Market House Deli and Cable Car Bake Shop)
pm:
As above and also
Phantom Manor
BTM
Indiana Jones
POC
(Also Walts, Plaza gardens, Caseys, Silver Spur, Blue Lagoon, Hyperion)
For entry am you needed to show your hotel ID. They were stopping people near the station to look at these and discouraging them from going further if they didnt have them, then you had to show them again as you went through a 'gate' just before bag check area. Without these passes you were not allowed through. I assume AP holders show that instead of hotel ID.
To stay after park closes you wear a special wrist band which you obtain from 5.00 by Main st Station (Also need to show hotel ID to get this)
This visit we only did am EMH and found it very busy but worth it just to get into the park and get a few rides done. Also you can position yourself for rides which arent open to be near the front. It was also good to get into the park without a massive queue outside.
Last year we did evening extra hrs and found it was still busy but again worth it.
Someone commented above about it being quieter in the evening so will be even quieter with EMH but there are less rides open so the queues for those will be longer. Also if the park is open for evening EMH its probably opened later in the am so people wont have been going as long.
There will also still be a lot of people about in the park without access to rides but allowed in shops and restaurants so the park itself will probably seem busier.