I like them, but I don't. I can imagine using one for school, (textbooks, notes and such) but I hate how they advertise them with people using them on a beach. They won't replace books until they have a way to replicate book-smell. Every different book has a different smell, old books, new books, books that have garlic hidden within them. It would be great if I never had to buy a book again, but they charge so much for books I could get for 50 cents in real life. (for example, to get the Lord of the Rings trilogy on the iPad, it's more than 15 dollars, I bought all of them at a Goodwill store for 50 cents, which includes The Hobbit)
In conclusion,
If you want to use it for school with textbooks and notes (and getting away with playing games in class) that's fine, but don't expect it to replace books. I suggest just getting a kindle of the cheapest variety, if you want it just to read books.