I always use this analogy: how/have hammers in the classroom benefited education. Once we divorce ourselves from the baggage of wanting to "prepare kids of the future" we can be more objective.
None of my English teachers have brought a hammer into the classroom. The Physics/science teachers need one of those 2 meter cartoon rubber hammers for some demonstrations. The shop class needs 40 different types of hammers, and 6 of them there is enough for each student to have one. The art class needs a couple hammers, and once in a while the teacher will borrow a complete set from the shop classroom. You can continue the logic for other areas.
Now that have set our mind right, what about computers. There are a number of places where computers are useful in school, but only rarely is it because they are a computer. In English class you need a word processor - there is no particular reason a dedicated word processor only machine wouldn't work just as well if a modern one existed. Likewise in all other classes, the important part isn't the computer, the important part is the software the computer is running.