Have you seen the new iPad 2 commercial? It shows the iPad 2 specifically as an educational tool! It can definitely be used by teachers and students for educational purposes.
I take my iPad 2 everywhere with me. Even though it's my personal device, I mostly use it for school and have app folders for my students to use.
The International Society for Technology in Education (ISTE) posted these 5 back-to-school apps for teachers. Two are free and the other three cost a small fee.