rinkwide - can't believe I left this off the 1st time - Have a great time while you explore the space....coast
TW1 - How much of a space nut are you? We are extreme so we spent the entire day at KSC and the next morning at the astronaut museum. The current shuttle mission is expected to land August 8th. The orbitor will most likely be stowed back in it's hanger before you go and with the rest grounded again the next launch in Sept is not happening.
This doesn't mean there isn't a lot to see anyway. KSC is on an island that is a nature preserve as well so lots of wildlife to view (birds, gators etc.).
There is a special tour ("VIP") that allows closest access to the launch pads etc. and we decided what the heck, we might as well go for it. We were at the ticket window at 9:45am and it was already sold out for the day. Remember though this was Christmas holiday time so perhaps more people than usual.
You can see alot of info about what there is to see/do at
http://www.kennedyspacecenter.com/
The "rocket garden" has rockets from our space past and it is very interesting to see them up close. There are several display areas, films, photo exhibits and the tour to the launch pads (not the VIP) is a must see. On that tour you also go to the building that houses the Saturn 5 and that is another amazing thing to view and learn more about our space history.
Opportunity exists for "lunch with and astronaut" which we did do but you really need to be a "space nerd" to do this. It's basically a decent meal with 150 others in a large room where they display a video and whatever astronaut they have "on duty" gives a little talk, answers questions and then will take photos with you.
Seeing the Enterprise - which is a full scale mock up of the Shuttle is great. When you are inside you can actually get the scope of how big that payload bay is etc. that they transport things in.
As I said it really depends on how big a space program fan you are. We spent the day but our car was one of the last in the lot.
Have a great time whatever you decide.
-ML