Oh jeez @sidsmommy3 I didn't even think of that! DD8 uses them at school (I think there's 2 per class?) and of course she now "NEEDS" one lol But I did find out through some digging that most of the time they're using them during free time and playing Angry Birds.
To answer the original question, I think it's good in theory, but realistically kids are going to play games/ drop them/ lose them/ spend entirely too much time on them. I do approve of integrating technology as much as possible, but I don't know that 12 year olds should have that much access to an iPad...
Our schools have BYOT (bring your own technology) days. They're allowed to bring iPads, iPods, or smart phones on certain days, announced in advance. Kids that don't bring a device are paired with those that do for lessons involving the technology. I think that integrating the technology into lessons is a good idea. However, the district has no plan for what to do if the devices that kids bring from home are lost or stolen. DD12 has an iPad because she got straight As all last year, but I won't let her take it to school. She has ADHD and won't be able to keep up with it. DS10 has an iPod, but he also has ADHD so I don't let him take it to school either.
I think letting kids have access to the technology is a great idea, but you have to make sure it's accessible to all and doesn't put the kids in danger. I also think the schools have to make sure that internet access is limited for all students to appropriate sites.