From what I am reading: (Room $ and dates are made up)
1. You have booked a cruise for 2013 and you are in room 1086 for that cruise.
2. You go to the future cruise desk and talk to the rep, asking to check the price of the same cruise and that category of room.
3. Rep will advise you what the cruise fare is as of that time. If is less that what you paid, yay. If not, then keep what you have.
4. Now here is the fun part about rebooking an existing cruise that you have reshopped, and the fare is less. With whom did you book the cruise originally? If it was
DCL, the rep can cancel that reservation and rebook it at the reduced rate and you will keep the same room. If you booked through a TA, you will need to place a new deposit on a different room in order to hold the lower rate and OBC. And NAME the TA for that booking. Once home, contact your TA and advise them what you have done, ask them to cancel your old reservation but to change the room number on the new reservation so that you keep the same room. As you have already paid a deposit on the first booking, you can have that amount transferred to the new booking, thus lowering the amount needed to be paid in full later. If you have a TA and you fail to name the TA when you rebook, it will cause a lot more issues, so make sure you do that. If you went through DCL, no worries.
5. Even tho you are going to be 12 months out, rates can and do go up. In May I deposited, through my TA the southbound repo from Vancouver to LA for 2012. 16 months in advance. The rates have already gone up, so even tho I will be on board in July next year, reshopping will not save me anything. So buyer beware.
6. No matter what, if you think you are ever going to cruise DCL again, rebook on board, Pick the cheapest room and the furthest out date, because the reduced deposit and OBC are not available once you get off the ship and you can push the date out until the right one is available.