There are several options available for upgrade. I think I would opt for a renovated room. If you have lots of points I hear the King rooms on the end of the wings are beautiful. There is a special name for them, but I can't remember it. The have turret balconies and think some have double balcony.
Other options:
1. A balcony
2. A view of Epcot fireworks (if you will be in your room at that time)
3. Club Level: You get breakfast foods and appetizers. Balconies are not available on club level, but you can get club level access if you are on another floor.
I also would recommend getting a room on the West Wing if you will be using the pool quite a bit, and make sure you are far away from where they are renovating if anyone in your group will be napping in the afternoon.
You can call the Dolphin and talk to a staff member about it. I found all the staff to be very helpful. Also you can e-mail your request at the swandolphin.com website.