Ok, here's the deal. I don't know how much the people in your group go to Disney, but these are my suggestions. If you are the DIS-aholic planner, then plan some events for everyone, like the cruises, and some meals, BUT, don't plan more than that for everyone. Just plan for your family. You may even want to post park hours, etc. We've gone with our best friends and this works great. The first time we went together, we thought we had to be together all of the time, but we found out by accident that splitting up is great!
We split by families or girls and boys or even dads take kids (probably to pool) and moms do something then another night moms take kids (probably bath and bedtime movie) and dads do something. We did the last thing by letting the dads go to evening EMH at MGM and moms did evening EMH at MK, but you could do golf or tea or spa or date night where the couples get a turn out by themselves, whatever your group is into.
Make sure to take lots of photos with photopass and share a CD! They will help you get a great pic of the whole group!