The concept is to help people install SDK (recently Alpha SDK with Qt5 and Wayland appeared and sometimes there are some issues with installation) and also help to write some simple apps, discuss OS components etc.

We don't need rooted phones, because only emulator is now available, so a laptop (or desktop ;)) with Linux/Windows/OSX is enough. I see it more like BYOL (Bring Your Own Laptop) type of event. First phones running Sailfish will be available at the end of this year or beginning of next year, because this Linux-based platform is completely new.