The following rules are if you are making a reservation directly with the hotel, and not buying a package.
The cancellation period is now a 5 days notice (the prior policy was 3 days).
A charge is placed on your credit card for the first night when you make the reservation, and that it might take up to 6 weeks to get a refund if you cancel prior to the 5 days of your scheduled arrival.
And that Hotel Guests no longer get "automatic" entry to Magic Mornings (used to be called Early Entry), now you must buy ParkHoppers from the Hotel front desk or as part of a travel package. Prior to this, Annual Passholders or folks that had other types of discounted tickets (such as military tickets) could enter on Magic Mornings. (Aka, your room charge slip will no longer allow you entrance to Magic Mornings, only a marked ParkHopper will get you in).
But there is a "fix" for the short term, as some folks were told the old policy when making their reservation. When you check in, ask the CM for a special "Magic Morning" pass if you need one. This will allow you into the park early. They will only issue one "pass" per person scheduled to stay in the room. Not sure how long they will do this, but Disney does understand that some folks who have already made reservations had this "perk" in mind