My eight year old son and I stayed at WL this summer. He liked the pool fine but . . . the slide is short, and after he went on it a few times the thrill was gone. Maybe part of it was that it was very crowded when we were there so he had to wait in line for five minutes or so just to go down the slide; also, we went to Typhoon Lagoon and Blizzard Beach early in our stay so he was a little jaded.
If you have time, you and your son should check out the pool early morning -- 7:00 a.m. or so. My son wanted to swim one last time before we left so we hit the pool early and there were several ducks enjoying the pool as well -- we didn't touch them, of course, or chase them but my DS was thrilled to be swimming in the middle of a group of three or four ducks (I got out of the water when the ducks joined us because ducks kind of gross me out). I'm not sure the pool is officially open that early, but there was a staff member there straightening up and she didn't have a problem with us being there -- and we were quiet in deference to those still sleeping. Just don't feed the ducks -- I made the mistake of giving them a piece of my english muffin and all hell broke loose --we finally had to flee to get away from them.