We stayed at the Dolphin last February, and we were on the 7th floor overlooking the Yacht/Beach Club, Boardwalk, and of course, Epcot. Great room. We had a balcony and I do remember that the room next to us didn't have a balcony (I think they do this so that the side of the building doesn't look cluttered with balconies and you don't feel like you're on top of the people next door). So if you have a resort view/lake view, there's a good chance that these rooms are what you would get.
I joined the SPG program before we went last Feb, and they were very accomodating with preferred views/location. If you want an Epcot view, request "an unobstructed view of Epcot" and ask if they have any king premier rooms available. They are the corner rooms that have windows on two sides of the room and two balconies. Ours was room # 7015, and it was on the far wing of the hotel.
Hope this helps!
ps--request a room on a higher floor, too. If I remember correctly, the wing on that side of the hotel has 9 floors, so ask if you can get floor 7 or higher. Then you won't have to worry about palm trees, etc blocking your view of Crescent Lake and Epcot.