Which ship/itinerary interests you? If you're planning to sail on the Dream or the Fantasy, they're contracted to use Port Canaveral, so it shouldn't be too difficult to figure out what their schedules will be. Their 2013 itineraries were released months before the Wonder the Magic, because their contracts with the port don't give them a whole lotta flexibility. The Fantasy currently sails every Saturday and rotates between the eastern and western caribbean itineraries.
Has your family indicated which dates will work best? When DH and I coordinated cruises for the extended family, there were so many conflicting activities -- sports, summer camp, different school schedules across several states -- on our last cruise there was only one week out of the whole summer that everybuddy could go. We still ended up leaving one little family behind because the mommy was preggers and her morning sickness did not mix well with seasickness.
Anyway, it would be helpful if you knew exactly which dates you're looking at, so that when DCL gets around to releasing their itineraries, you'll be ready to book the first day. And it wouldn't hurt to have a Plan B and even a Plan C for different itineraries on different cruise lines, just in case someone balks at the Disney price tag, or the same boring itineraries.