As with all great new ideas (and the Raspberry Pi is a great idea) there are lots of misconceptions and half-truths. So before you buy a Pi, read this first!
If you threw away your PC based machines when you fell in love with the iPad (or similar device) the Pi might be a good way to get your students interested in what actually happens inside a computer. For older students doing Computer Studies, the Pi is great because they can experiment with a computer that is separate to the main school network. You’d never allow students to ‘mess’ with the OS on a curriculum machine.