Today, the RPIZW has been announced. Only hours ago, and (almost) all retailers are sold out. This RPI model is the same as the Pi Zero, except it has WiFi and BT built in.
Not sure how good the WiFi is or how many simultaneous connections we could have, but I thought I would pick one up to experiment.
Yes, it may be underpowered, yes it may not sport many simultanious connections, yes it may not broadcast very far. However, a $20 ($10 RPI, $10 32GB SD) all-in-one board the size of two fingers would be quiet a showcase piece for us.
Hackaday wrote a nice article on it: http://hackaday.com/2017/02/28/10-raspberry-pi-zero-w-the-w-means-wifi-bluetooth/
If you want to pick one up as well, hurry! : https://thepihut.com/products/raspberry-pi-zero-w?variant=30332705425. It's from the UK and costs $20 shipped. It's the only choice right now and (if like the Zero 1) will be for a while.