quite a warm time of the year to stay in Dubai on holidays... so prepare yourself for very warm weather ;-)
Have not stayed with kids yet there, but I know quite some people who have enjoyed the Atlantis The Palm hotel, which has a massive water Parc, aquarium, et..
Yes very warm there but had plans on going back to our 2nd home in Sri lanka for 3 weeks here in July but decided to hold off over the April issues there. You have mentioned the exact place I have my sights on and think this is where we will end up. Looks to be lots to do right at the complex for two young grand children..