I received negative feedback about using adobe flash for a new website for children. Websites like club penguin and others made specifically for children have been built with adobe flash, yet I have had some very negative feedback about using flash for a new site, that would be in the same market as these established sites.
It won't work on the iPad. Children are so into tablets and touch. They want to touch all screens!
Daniel is right in that Flash content won't work directly on your iPad's Safari, but Flash contents can actually be turned into iPhone and iPad apps (and even Android) very easily and it's a fine tool for building cross platform 2D game contents. Apple has long lifted the ban on cross platform tools and external runtime. We have published two apps using Flash and they work great.