I made ressie for thanksgiving (the weekend before) for this yr. in Feb. I made ressie for the first week in Jan. 2008 (still on christmas break) Jan. 2007 knowing that these are "HOT" weekends. We just came back from a week stay at the Ft. Aug. 12-19 and I made ressie in June. So like others have said it depends on the time of year.
This was the first time we stayed in Aug. and for a week. We got the FL resident water park after 2p pass. We've never done the water parks. It was fantastic. We got front row parking and we closed the park. The last hr. is empty so we rode many rides 2 and 3 times.

So as far as planning I still plan. I check to see where the extra magical hrs. are in what parks in the EVENING. Which we all love going to MK when the sun is down. We stayed out of the theme parks during the day-too many people and too hot. Love those water parks!!
We are 30 mins. from Disney so we enter the Ft. right at 1p, set up and head to the water parks or in the cooler months we head to whichever park offered extra magical hrs.-again I look up that info. ahead of time. I also, buy all the groceries and plan the meals ahead of time since it's cheaper AND it's easier on time and fustration to seek out a Publix, Winn Dixie etc. over there. So for me there is still planning and like any other camping trip-making sure the kids (and DH)

bring the right clothes (bathing suit, flip flops etc.)
We LOVE Disney's FTW. in the "off" season. We camp at the state parks as well but FTW is a quick drive, cheaper on gas when you're pulling a 26TT and you sewer right there. You get what you pay for. We love riding our bikes around the FT and to WL. Watch the fireworks and the electrical water Pagent on the FT beach /marina. of course, the campfire and sing along too. What's not to like!?
Ok, I'll stop rambling now...