Why on earth would you lock down an iPad? We have about 100 iPads at my school (its 1-1, iPads for 10-12 and laptops/chromebooks for the older kids) and very few technical glitches. But then, ours arent locked down and are on an open wireless network. I have no problem managing the use of the iPads in my classsroom, they are used when and how I say. Sysadmins and others tend to have a very narrow focus on tech in schools, at least thats my experience. Open standards and a good infrastructure is whats needed, not lockdowns, bureacracy and management.
The device itself is a tool, its what I as a teacher do with it that makes a difference. I teach math and science at a school near Stockholm in Sweden. All my students in math turned in their own video explaining how to separate any number into ones, tens, hundreds and so on the other week. I get the kids to think and act and I get a great overview of their math vocabulary and basic thinking. We use it to watch videos with short lessons and explanations of problems, to do homework and write on our classroom blog.
We use them for documenting science projects by writing, snapping pictures and making videos, we train multiplication tables and watch clips from Youtube and sources like myself and other teachers at the school.
The iPad is a complementary tool for my teaching. What I teach doesnt change when you add technology, but how I can teach and how the kids can learn does. Last year I had three computers and 34 kids at a different school. I still teach the same things, but I can do a lot more in the same time now.