They are shipping (albeit slowly). I bought two (for both of my daughters) and here's why:
1. Yes, it's *just* a raspberry pi, but it's also got some other parts (wifi, speaker, case, stickers) and the custom bluetooth keyboard (great for small hands; not so much for adults.
2. KanoOS is what's really amazing. It's free, open, and you can load it on a regular rpi (with some work):
http://www.kano.me/downloads. IMHO, this is where the magic happens. It's nicely done kids-focused ui, and there's tools for learning how to use the computer and build things (simple games). It also comes with a nice booklet that guides kids through assembly and startup up the thing. My 9-year-old put hers together with about 5 seconds worth of help from me (plugging in the hdmi cable).
3. I wanted to support this project. They *did* build a custom piece of hardware (the keyboard), but they also did some amazing working assembling the software.
I think I paid $250 total for two kano kits. If you want to get kids into computing, it's a great buy. If you want to dabble with a raspberri pi for yourself, just get the cheap kit.