Here's a thoughtful Wired article found online at Gizmodo about iPads for kids.
Brad Moon punctuates several valid points for purchasing iPads for kids, especially for "educational assistance...as a way to enhanced educational multimedia content." This is timely information, with the release of the new iPad3.
The Case for Buying iPads for Your Kids
My wife and I made the decision last year to equip our kids with iPads, something that might have sounded excessive only the year before. Now it only makes sense. When you do the math, an iPad (or tablet of choice) for a child makes sense; when you have more than one child, the upfront hardware expenditure is higher, but the savings are even greater.