Every school kid should be given one, its a great way to teach IT and give kids an understanding of the computer parts and how a computer really works as opposed to just learning Microsoft Office skills in class. This is the main goal of the Raspberry Pi Foundation and also why the price point is so low!
I've ordered mine and can't wait to get it. I had the original and skipped the B+ model.
There are so many add-ons and projects that can be done with these. Personally I've used mine for learning a bit of Python, some bit-coin mining and also to set-up my own email server (not for permanent use).