Here is the info I saved a while ago about Water Parks at WDW:
Blizzard Beach is not for relaxing. There is limited beach space, and with 21 slides, the focus is on attractions that draw the energetic crowd. Snowcapped Mt. Gushmore is the icon of the park, you can get up to the top by chairlift or stairs, but how you get down is up to you. Teamboat Springs, a white-water faft that seats five, is plenty zippy and a good ride to try first since the entire family goes together. There are also mat rides, tube rides, and full-throttle plunges!
At 120 feet, Summit Plummet is the highest and fastest flume ride in the country. Sliders rach speeds of 55 mph, a full 20 mph faster than Space Mountain- and here you dont even have a car. This slide is not for the faint at heart, and the height requirement is 48 inches. And when you cross your legs, you better cross your fingers, too!
Not quite up for that? Kids love the foam rubber sleds of Toboggan Racer, where 8 riders face off for a straight shot down the mountain. Other fun choices include the inner-tube slides of Runoff Rapids and Snow Stormers, a mock slalom run. These rides are like potato chips - once you start, its hard to stop - and most kids clamor to do them again and again.
If your older kids insist that its Blizzard Beach or nothing, dont think younger siblings will be bored. The kiddie area, Tike's Peak, is a small replica of Mount Gushmore and offers a spray pond, a wading pool, and lots of kid-sized slides and tube rides. There are even separate toddler slides to insure that your 2 year old wont be trampled by over-enthusiastic kindergarteners. Ski Patrol Training Camp is designed for preteens that are too hip for Tike's Peak but nt quite up to the full-size Mount Gushmore attractions. (Note: Kids under 10 must be accompanied by an adult). Look for the Cool Runners tube rides, the iceberg walk, and slides so wide the entire family can go down side by side.
Blizzards Beach's newest slide ride is Downhill Double Dipper, an individual tube ride that sends tou through a water curtain and tunnel before you emerge through another water curtain, are flumed down a hill, and wind up in a pool at the bottom. Everyone seems to finish this ride with a smile or a giggle.
TYPHOON LAGOON
The story here: A small village was struck by a tidal wave, an earthquake, and a typhoon! The huge, shady beach are is full of palms, and there are many small nooks and coves where parents can flop on a lounge chair while the kids explore.
The slides are smaller at Typhoon Lagoon and the kiddie areas are not as big as Blizzard Beach's, but just wait until you see the pool. The wave pool at Typhoon Lagoon is the size of three football fields and designed for actual surfing. Even with tubes, this is serious stuff. Certain hours are designated for body surfing, and a foghorn blast alerts you to when a big 'un is underway. (Don't take small children in too deep when the wave machine is cranked up. During the five foot waves, you can count on a pool full of shrieking teenages bearing down upon your head every 90 seconds!)
While the park centers around the surfing pool, there are also plenty of rides and slides, including Humunga Kawabunga, which accelerates sliders to speeds of 30mph, and a squeal-ripping corkscrew tube ride called Mayday Falls. Often overlooked because of its out of the way location is Shark Reef, where snorkelers swim among tropical fish. Equipment is provided and an instructor talks you through the basics. It's a safe, fun, first-snorkeling experience.
I think myself that the Typhoon Lagoon is a little more "small kid friendly" then the Blizzard Beach, but the kids will have fun in either of those.